cholecystokinin and Disease-Models--Animal

This is a summary of the virtual presentation given at the 2021 meeting of the Society for Research on the Cerebellum and Ataxias, https://www.meetings.be/SRCA2021/ , where the therapeutic potential of the CCK-CCK1R pathway for treating diseases involving Purkinje cell degeneration was presented. Spinocerebellar ataxia type 1 (SCA1) is one of a group of almost 50 genetic diseases characterized by the degeneration of cerebellar Purkinje cells. The SCA1 Pcp2-ATXN1[30Q]D776 mouse model displays ataxia, i.e. Purkinje cell dysfunction, but lacks progressive Purkinje cell degeneration. RNA-seq revealed increased expression of cholecystokinin (CCK) in cerebella of Pcp2-ATXN1[30Q]D776 mice. Importantly, the absence of Cck1 receptor (CCK1R) in Pcp2-ATXN1[30Q]D776 mice conferred a progressive degenerative disease with Purkinje cell loss. Administration of a CCK1R agonist to Pcp2-AXTN1[82Q] mice reduced Purkinje cell pathology and associated deficits in motor performance. In addition, administration of the CCK1R agonist improved motor performance of Pcp2-ATXN2[127Q] SCA2 mice. Furthermore, CCK1R activation corrected mTORC1 signaling and improved the expression of calbindin in the cerebella of AXTN1[82Q] and ATXN2[127Q] mice. These results support the Cck-Cck1R pathway is a potential therapeutic target for the treatment of diseases involving Purkinje neuron degeneration.

Topics: Animals; Ataxia; Ataxin-1; Cerebellum; Cholecystokinin; Disease Models, Animal; Mice; Mice, Transgenic; Purkinje Cells; Receptors, Cholecystokinin; Spinocerebellar Ataxias

This chapter describes the various animal models that seem relevant to the development of anxiolytic drugs, as well as the human models of induced anxiety, or more precisely the panic inducers including cholecystokinin. It is also mentioned the theoretical model of Deakin and Graeff which seems to keep all its relevance. The knock animals are evoked as relevant tools as well as a new optogenetic technique that needs to be used in this field.

Topics: Animals; Anti-Anxiety Agents; Anxiety; Anxiety Disorders; Cholecystokinin; Disease Models, Animal; Drug Discovery; Humans; Optogenetics

Coeliac disease is a chronic, small intestinal, immune-mediated enteropathy caused by a permanent intolerance to dietary gluten in genetically predisposed individuals. Clinical studies have found that intestinal cholecystokinin secretion and gallbladder emptying in response to a fatty meal are impaired before coeliac patients start the gluten-free diet (GFD).. However, it was never really appreciated whether coeliac disease is associated with gallstones because there were very few studies investigating the mechanism underlying the impact of coeliac disease on the pathogenesis of gallstones.. We summarize recent progress on the relationship between coeliac disease and gallstones and propose that coeliac disease is an important risk factor for gallstone formation because defective intestinal cholecystokinin secretion markedly increases susceptibility to cholesterol gallstones via a mechanism involving dysmotility of both the gallbladder and the small intestine. Because GFD can significantly improve the coeliac enteropathy, early diagnosis and therapy in coeliac patients is crucial for preventing the long-term impact of cholecystokinin deficiency on the biliary and intestinal consequences. When gluten is reintroduced, clinical and histologic relapse often occurs in coeliac patients. Moreover, some of the coeliac patients do not respond well to GFD.. It is imperative to routinely examine by ultrasonography whether gallbladder motility function is preserved in coeliac patients and monitor whether biliary sludge (a precursor of gallstones) appears in the gallbladder, regardless of whether they are under the GFD programme. To prevent gallstones in coeliac patients, it is urgently needed to investigate the prevalence and pathogenesis of gallstones in these patients.

Topics: Animals; Celiac Disease; Cholecystokinin; Disease Models, Animal; Forecasting; Gallbladder Emptying; Gallstones; Humans; Intestine, Small; Mice, Knockout; Receptors, Cholecystokinin; Risk Factors

In recent years, studies have advocated neuropeptide systems as modulators for the behavioral states found in mood disorders such as depression and anxiety disorders. Neuropeptides have been tested in traditional animal models and screening procedures that have been validated by known antidepressants and anxiolytics. However, it has become clear that although these tests are very useful, neuropeptides have distinct behavioral effects and dose-dependent characteristics, and therefore, use of these tests with neuropeptides must be done with an understanding of their unique characteristics. This review will focus on the behavioral actions of neuropeptides and their synthetic analogs, particularly in studies utilizing various preclinical tests of depression and anxiety. Specifically, the following neuropeptide systems will be reviewed: corticotropin-releasing factor (CRF), urocortin (Ucn), teneurin C-terminal associated peptide (TCAP), neuropeptide Y (NPY), arginine vasopressin (AVP), oxytocin, the Tyr-MIF-1 family, cholecystokinin (CCK), galanin, and substance P. These neuropeptide systems each have a unique role in the regulation of stress-like behavior, and therefore provide intriguing therapeutic targets for mood disorder treatment.

Topics: Animals; Anxiety; Arginine Vasopressin; Behavior, Animal; Cholecystokinin; Corticotropin-Releasing Hormone; Depression; Disease Models, Animal; Galanin; Humans; MSH Release-Inhibiting Hormone; Neuropeptide Y; Neuropeptides; Neuropsychological Tests; Oxytocin; Social Behavior; Urocortins

Humans in many countries are currently experiencing what has been called an epidemic of obesity. That is, the average body weight (and amount of fat stored in the body) is increasing over years, carrying with it a multitude of associated medical, psychological, and economic problems. While there is no shortage of possible causes of this epidemic, increased availability and consumption of high-fat (HF), calorically dense and generally quite palatable food is often touted as a likely culprit. In order to better assess the impact of consuming a diet with those qualities, we have developed a well-controlled animal model in which the effects of chronic consumption of a high-fat diet can be dissociated from those of becoming obese per se. Long-Evans rats are fed one of two semipurified pelleted diets, a HF diet that contains 20% fat by weight and a low-fat (LF) diet that contains 4% fat by weight. Pair-fed animals consume the HF diet but are limited to the daily caloric intake of LF rats. Another group receives pelleted chow. Relative to animals consuming diets low in fat, HF animals weigh more, have more carcass fat, are hyperinsulinemic and hyperleptinemic, and are insulin resistant. HF-fed animals, independent of whether they become obese or not, also have central insulin and MTII insensitivity. Finally, HF rats have a down-regulated hypothalamic apo A-IV system that could contribute to their hyperphagia.

Topics: Animals; Body Weight; Cholecystokinin; Dietary Fats; Disease Models, Animal; Energy Intake; Energy Metabolism; Homeostasis; Humans; Insulin; Obesity; Rats; Time Factors

The biological clock mechanism was studied in both non-insulin-dependent and insulin-dependent diabetic model rats. Otsuka Long Evans Tokushima Fatty (OLETF) rats were used as a non-insulin-dependent model. Streptozotocin (STZ, 100 mg/kg, i.p.) was administered to 8- to 10-week-old Wistar rats for an insulin-dependent diabetic model. Both young non-diabetic OLETF and STZ-induced diabetic rats needed more days for re-entrainment to a new light-dark cycle than control rats on activity rhythm. In young OLETF rats, dim-light-induced Fos expression (50 and 100 lux) was significantly decreased in the suprachiasmatic nucleus. In diabetic OLETF rats, Fos expression was decreased by the exposure of light at 300 lux. In STZ-induced diabetic rats, Fos expression was also decreased by 300 lux of light. In OLETF rats, the phase delay by glutamate application was significantly smaller than that in control rats on the suprachiasmatic nucleus neuronal (SCN) activity rhythms. On the other hand, the same level of phase delay was observed between control and STZ-induced diabetic rats by glutamate application. These results suggest that entrainment function is disordered in OLETF rats before the onset of hyperglycemia. To clarify the entrainment function of STZ-induced diabetic rats, however, further study is necessary.

Topics: Animals; Biological Clocks; Cholecystokinin; Circadian Rhythm; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Models, Animal; Motor Activity; Proto-Oncogene Proteins c-fos; Rats; Rats, Inbred OLETF; Rats, Wistar; Serotonin; Streptozocin; Suprachiasmatic Nucleus

Anorexia during infection is thought to be mediated by immunoregulatory cytokines such as interleukins 1 and 6 and tumor necrosis factor. This article reviews the potential mechanisms of action by which these cytokines are thought to suppress food intake during infection and examines the proposition that blocking of cytokine activity might be one approach to improving food intake of the infected host.

Topics: Acute-Phase Reaction; Animals; Anorexia; Cholecystokinin; Cytokines; Dinoprostone; Disease Models, Animal; Eating; Fever; Gastroparesis; Humans; Infections; Inflammation Mediators; Leptin; Vagus Nerve

Topics: Administration, Oral; Animals; Bile; Bile Acids and Salts; Cholecystokinin; Deoxycholic Acid; Digestive System Physiological Phenomena; Disease Models, Animal; Endotoxins; Intestinal Absorption; Lipopolysaccharides; Rats

The desire to understand the pathophysiology of schizophrenia has inspired an explosion in research over the past decade. This review highlights some key studies that have led to fundamental changes in our understanding of this disorder, focusing on the search for genes in schizophrenia, as well as several recent alternatives to the original dopamine hypothesis of schizophrenia. Advances in genetic methodology have allowed schizophrenia researchers to conduct genome-wide searches for susceptibility genes. Although these studies have identified several regions that demonstrate potential linkage with schizophrenia, a definitive genetic cause has not yet been proved. Recent neurochemical hypotheses have focused on the cortical amino acid neurotransmitter systems (i.e., glutamate and GABA), while anatomical studies suggesting abnormal brain development and premorbid functional deficits have led some researchers to propose a neurodevelopmental origin for schizophrenia. A sizable database can be marshaled in support of each of these ideas, but none as yet fully explain the biological basis of schizophrenia.

Topics: Animals; Aspartic Acid; Brain; Cholecystokinin; Disease Models, Animal; Dopamine; Entorhinal Cortex; gamma-Aminobutyric Acid; Genetic Linkage; Genetic Markers; Glutamic Acid; Humans; RNA, Messenger; Rodentia; Schizophrenia

Cholecystokinin (CCK) act as hormones and neuropeptides on central and peripheral CCK receptors. The application of modern molecular biological techniques has identified two CCK receptors, CCK-A receptor (CCKAR) and CCK-B/gastrin receptor (CCKBR). The genes of CCKAR and CCKBR consist of five exons interrupted by four introns. We have reported that OLETF rats, which have been established as an animal model of NIDDM, revealed no expression of CCKAR gene (a naturally occurring CCKAR gene knockout rat). Pancreatic exocrine functions in OLETF rats are regulated by all neural and peptidergic agents except CCK. Therefore, we have proposed that OLETF rats may be a useful experimental model for examining the biological functions of the CCKAR.

Topics: Amino Acid Sequence; Animals; Cholecystokinin; Cloning, Molecular; Diabetes Mellitus, Type 2; Disease Models, Animal; Humans; Molecular Sequence Data; Pancreas; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Receptors, Cholecystokinin

Until recently, basic science studies, both behavioural and electrophysiological, have concentrated on the antinociceptive actions of opioids primarily gauged against acute nociceptive responses. However, of more relevance to clinical situations are the actions of opioids in more persistent/prolonged pain states. This review sets out to examine the central actions of opioids against nociception of inflammatory origins. The first section deals with the response of the endogenous opioid system to the development of an inflammatory state and the second examines the ability of exogenous opioids to modulate inflammatory nociception. There are complex changes in the roles of endogenous opioids, in particular dynorphin, at the spinal level after inflammation although the physiological consequences remain unclear. With regard to exogenous opioids, the effectiveness of spinal morphine is rapidly enhanced after inflammation, likely to be due to changes in the interaction between the peptide cholecystokinin and the mu opioid receptor. The ability of inflammatory processes to alter both endogenous opioids and morphine analgesia at the spinal level illustrates the considerable degree of plasticity observed in opioid function.

Topics: Analgesia; Animals; Carrageenan; Cholecystokinin; Disease Models, Animal; Inflammation; Injections, Spinal; Narcotics; Opioid Peptides; Pain; Receptors, Adrenergic, alpha-2; Receptors, Opioid; Spinal Cord; Synaptic Transmission

This review describes the neuropathology and pathophysiology of interneurons in dorsal hippocampus of the adult rat subjected to transient global cerebral ischemia. The object is to verify if the interneurons die or survive after an ischemic insult, and study if ischemia changes GABA inhibition in the period preceding delayed CA1 pyramidal cell death. The findings are discussed from the point of the hypothesis that loss of GABA inhibition may result in excitatory hyperactivity (possibly epilepsy) and excitotoxic glutamate release. Thereby, early ischemic damage to interneurons may exacerbate the ischemic process resulting in the major and delayed CA1 cell death in hippocampus. Interneurons, located in dentate hilus, and a small number of interneurons located in the mossy fiber layer are selectively lost after ischemia. These interneurons contain somatostatin and neuropeptide Y, but the inhibitory or excitatory nature of them is unknown. However, counts of all hippocampal cells immunoreactive for glutamic acid decarboxylase showed that the GABA interneurons survive ischemia. It is therefore suggested that the vulnerable interneurons in hilus and the mossy fiber layer do not contain GABA. As the GABA interneurons, other hippocampal interneurons also survive ischemia. Among these, the CA1 and CA3 interneurons containing neuropeptide Y demonstrate permanently reduced immunoreactivity for neuropeptide Y, evident 1-2 days after ischemia. Another subpopulation transiently shows a decrease in immunoreactivity for parvalbumin approximately 4 days after ischemia. These results are in contrast to the finding that protein synthesis in hippocampal interneurons returns to preischemic levels 9 hours after ischemia. The integrity between excitation and inhibition in CA1 is unchanged in hippocampal slices taken from animals 1-2 days after ischemia. Furthermore, GABA can readily be released upon potassium stimulation in the period preceding CA1 pyramidal cell death. Binding to hippocampal benzodiazepine sites, however, declines prior to ischemic CA1 pyramidal cell death. It is demonstrated that administration of diazepam and GABA uptake inhibitors during this period offers postischemic neuron protection in CA1. There is no conclusive evidence of excitatory hyperactivity preceding ischemic CA1 pyramidal cell death. On the contrary, results from Chang et al. (1) suggest that ischemic loss of interneurons in the dentate hilus is associated with an increase in inhibition. Howe

Topics: Animals; Autoradiography; Brain Ischemia; Calcium-Binding Proteins; Cell Death; Cholecystokinin; Disease Models, Animal; gamma-Aminobutyric Acid; Glutamate Decarboxylase; Hippocampus; Interneurons; Neuropeptide Y; Pyramidal Cells; Rats; Receptors, GABA; Somatostatin

Potent and selective CCK-B agonists with good bioavailability have been designed by modifying the natural CCK-8 peptide. Thus, BC 264 [Boc-Tyr(SO3H)-gNle-mGly-Trp-Me(Nle)-Asp-PheNH2] is a highly potent (0.15 nM) and selective agonist for CCK-B receptors which cross the blood brain barrier. Following i.v. injection of [3H]pBC 264 in mouse, the ligand was found in its intact form in brain tissue. Analgesic studies and in vivo binding experiments have shown that the CCKergic system could modify the release of endogenous enkephalins, whereas mu and delta opioid receptor activation modulates the release of endogenous CCK. Behavioural studies performed after local injection of CCK-8 or BC 264 into the postero-median part of the nucleus accumbens have shown the involvement of CCK-A receptors in motivation and/or emotional states of rats. In the anterior part, CCK-B receptor stimulation could be involved in attention and memory processes. BC 264 systemically administered in mice increased fear and/or "anxiety" in the black and white box test. In the elevated plus maze, BC 264 increased the emotional responses of the "anxious" rat and decreased these responses in "non anxious" animals. These results suggest that endogenous CCK could play a critical role in mood modulation through CCK-A/CCK-B receptor stimulation. Dysfunctioning of the CCK-A/CCK-B pathways could be implicated in anxiety and panic attacks.

Topics: Animals; Behavior, Animal; Biological Availability; Brain; Cholecystokinin; Disease Models, Animal; Emotions; Mice; Nucleus Accumbens; Pain; Rats; Receptors, Cholecystokinin

Topics: Acute Disease; Animals; Cholecystokinin; Disease Models, Animal; Humans; Pancreas; Pancreatitis; Rats; Regeneration; Remission, Spontaneous

Topics: Afferent Pathways; Animals; Bombesin; Brain Mapping; Calcitonin; Calcitonin Gene-Related Peptide; Cholecystokinin; Corticotropin-Releasing Hormone; Disease Models, Animal; Endorphins; Feeding Behavior; Glucagon; Humans; Insulin; Motilin; Nerve Tissue Proteins; Neuropeptide Y; Neurotensin; Obesity; Pancreatic Polypeptide; Satiety Response; Somatostatin; Species Specificity; Stress, Psychological; Taste; Thyrotropin-Releasing Hormone

The patient with gastric ulcer (GU) has abnormal reflux of bile-containing duodenal contents into the stomach. Antral gastritis is prominently associated with GU and is more extensive with severe reflux and with ulcer chronicity and probably when bile salts are accompanied by other constituents of duodenal fluids. Smoking is significantly associated with GU, and it produces reflux in normal subjects and in patients with duodenal ulcer, which in turn is commonly associated with GU. Reflux has not been shown to precede either the gastritis or the gastric ulcer and probably persists despite ulcer healing. The pyloric spincter in the patient with GU probably contracts subnormally to endogenous or exogenous secretin or CCK. This can be explained by associated hypergastrinemia since antral acidification improves the response. Because the pylorus may be usually open, abnormal reflux may be related as much or more to disturbances of other gastroduodenal functions known to control the movement of chyme through what may be a relatively passive pyloric zone. Speculation from animal models implicates bile reflux in aspirin-induced and shock-related gastric ulceration and assigns to bile a possible explanation, in part at least, for the apparent therapeutic efficacy of a carbenoxalone derivative and an antipepsin agent. Similar speculation warrants a search in the patient with GU for abnormalities of gastroduodenal peristalsis-related electric activity and for impaired release of secretin, possibly from antral cells of production. Possible abnormal purinergic inhibition of the gastric fundus and pylorus also warrants further study.

Topics: Animals; Bile; Cholecystokinin; Disease Models, Animal; Duodenum; Gastric Mucosa; Gastrins; Gastritis; Gastroesophageal Reflux; Humans; Pyloric Antrum; Pylorus; Secretin; Stomach Ulcer

Synaptic impairment and loss are an important pathological feature of Alzheimer's disease (AD). Memory is stored in neural networks through changes in synaptic activity, and synaptic dysfunction can cause cognitive dysfunction and memory loss. Cholecystokinin (CCK) is one of the major neuropeptides in the brain, and plays a role as a neurotransmitter and growth factor. The level of CCK in the cerebrospinal fluid is decreased in AD patients. In this study, a novel CCK analogue was synthesized on the basis of preserving the minimum bioactive fragment of endogenous CCK to investigate whether the novel CCK analogue could improve synaptic plasticity in the hippocampus of the APP/PS1 transgenic mouse model of AD and its possible molecular biological mechanism. Our study found that the CCK analogue could effectively improve spatial learning and memory, enhance synaptic plasticity in the hippocampus, normalize synapse numbers and morphology and the levels of key synaptic proteins, up-regulate the PI3K/Akt signaling pathway and normalize PKA, CREB, BDNF and TrkB receptor levels in APP/PS1 mice. The amyloid plaque load in the brain was reduced by CCK, too. The use of a CCKB receptor antagonist and targeted knockdown of the CCKB receptor (CCKBR) attenuated the neuroprotective effect of the CCK analogue. These results demonstrate that the neuroprotective effect of CCK analogue is achieved by activating the PI3K/Akt as well as the PKA/CREB-BDNF/TrkB signaling pathway that leads to protection of synapses and cognition.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Brain-Derived Neurotrophic Factor; Cholecystokinin; Cognition; Disease Models, Animal; Hippocampus; Mice; Mice, Transgenic; Neuronal Plasticity; Neuroprotective Agents; Phosphatidylinositol 3-Kinases; Presenilin-1; Proto-Oncogene Proteins c-akt; Signal Transduction

A significant proportion of temporal lobe epilepsy (TLE) patients experience drug-resistant seizures associated with mesial temporal sclerosis, in which there is extensive cell loss in the hippocampal CA1 and CA3 subfields, with a relative sparing of dentate gyrus granule cells and CA2 pyramidal neurons (PNs). A role for CA2 in seizure generation was suggested based on findings of a reduction in CA2 synaptic inhibition (Williamson and Spencer, 1994) and the presence of interictal-like spike activity in CA2 in resected hippocampal tissue from TLE patients (Wittner et al., 2009). We recently found that in the pilocarpine-induced status epilepticus (PILO-SE) mouse model of TLE there was an increase in CA2 intrinsic excitability associated with a loss of CA2 synaptic inhibition. Furthermore, chemogenetic silencing of CA2 significantly reduced seizure frequency, consistent with a role of CA2 in promoting seizure generation and/or propagation (Whitebirch et al., 2022). In the present study, we explored the cellular basis of this inhibitory deficit using immunohistochemical and electrophysiological approaches in PILO-SE male and female mice. We report a widespread decrease in the density of pro-cholecystokinin-immunopositive (CCK

Topics: Animals; CA2 Region, Hippocampal; Cholecystokinin; Disease Models, Animal; Epilepsy, Temporal Lobe; Female; Hippocampus; Humans; Interneurons; Male; Mice; Pilocarpine; Seizures; Status Epilepticus

Parkinson's disease (PD) is the second most common neurodegenerative disease, and no treatment is available to stop its progression. Studies have shown that the colonic pathology of PD precedes that of the brain. The 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model and the human A53T α-synuclein (α-syn) transgenic PD mouse model show colonic pathology and intestinal dopaminergic neuronal damage, which is comparable to the intestinal pathology of PD. Cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), which are brain-gut peptides, have neurotrophic and anti-inflammatory properties. Two GLP-1R agonists have already shown robust effects in phase II trials in PD patients. However, whether they have beneficial effects on colonic pathology in PD remains unclear. In this study, MPTP-treated mice and human A53T α-syn transgenic mice were intraperitoneally injected with a CCK analogue or Liraglutide, a GLP-1 analogue, once a day for 5 weeks. Levels of colonic epithelial tight junction proteins including occludin and zonula occludens-1 (ZO-1), inflammatory biomarkers including inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α), brain-derived neurotrophic factor (BDNF), tyrosine hydroxylase (TH) and α-syn were analyzed. The results show that the CCK analogue and Liraglutide both restored the disruption of intestinal tight junction, reduced colonic inflammation, inhibited colonic dopaminergic neurons reduction and the accumulation of α-syn oligomers in the colon of both PD mice models. This study suggested that CCK or GLP-1 analogues could be beneficial to the improvement of leaky gut barrier, inflammation, dopaminergic neuron impairment and accumulation of α-syn in the colon of PD patients.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; alpha-Synuclein; Animals; Cholecystokinin; Colon; Disease Models, Animal; Dopaminergic Neurons; Glucagon-Like Peptide 1; Humans; Inflammation; Liraglutide; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neurodegenerative Diseases; Parkinson Disease; Tight Junctions

Acute pancreatitis (AP) is a major, globally increasing gastrointestinal disease and a biliary origin is the most common cause. However, the effects of bile acids (BAs), given systemically, on the pancreas and on disease severity remains elusive. In this study, we have investigated the roles of different circulating BAs in animal models for AP to elucidate their impact on disease severity and the underlying pathomechanisms. BAs were incubated on isolated acini and AP was induced through repetitive injections of caerulein or L-arginine; pancreatic duct ligation (PDL); or combined biliopancreatic duct ligation (BPDL). Disease severity was assessed using biochemical and histological parameters. Serum cholecystokinin (CCK) concentrations were determined via enzyme immunoassay. The binding of the CCK1 receptor was measured using fluorescence-labeled CCK. In isolated acini, hydrophobic BAs mitigated the damaging effects of CCK. The same BAs further enhanced pancreatitis in L-arginine- and PDL-based pancreatitis, whereas they ameliorated pancreatic damage in the caerulein and BPDL models. Mechanistically, the binding affinity of the CCK1 receptor was significantly reduced by hydrophobic BAs. The hydrophobicity of BAs and the involvement of CCK seem to be relevant in the course of AP. Systemic BAs may affect the severity of AP by interfering with the CCK1 receptor.

Topics: Acute Disease; Animals; Arginine; Bile Acids and Salts; Ceruletide; Cholecystokinin; Disease Models, Animal; Hydrophobic and Hydrophilic Interactions; Mice; Pancreas; Pancreatitis

Spinocerebellar ataxias (SCAs) are a group of genetic diseases characterized by progressive ataxia and neurodegeneration, often in cerebellar Purkinje neurons. A SCA1 mouse model, Pcp2-ATXN1[30Q]D776, has severe ataxia in absence of progressive Purkinje neuron degeneration and death. Previous RNA-seq analyses identify cerebellar upregulation of the peptide hormone cholecystokinin (Cck) in Pcp2-ATXN1[30Q]D776 mice. Importantly, absence of Cck1 receptor (Cck1R) in Pcp2-ATXN1[30Q]D776 mice confers a progressive disease with Purkinje neuron death. Administration of a Cck1R agonist, A71623, to Pcp2-ATXN1[30Q]D776;Cck

Topics: Animals; Ataxin-1; Atrophy; Behavior, Animal; Calbindins; Chemokines, CC; Cholecystokinin; Disease Models, Animal; Female; Genetic Predisposition to Disease; Guanine Nucleotide Exchange Factors; Male; Mechanistic Target of Rapamycin Complex 1; Mice, Inbred C57BL; Mice, Knockout; Motor Activity; Nerve Degeneration; Neuropeptides; Purkinje Cells; Signal Transduction; Spinocerebellar Ataxias; Tetragastrin

Topics: Animals; Carcinoma, Hepatocellular; Cell Line, Tumor; Chemokines, CC; Cholecystokinin; Diet, High-Fat; Disease Models, Animal; Female; Gene Knockout Techniques; Hepatic Stellate Cells; Humans; Liver; Liver Neoplasms; Male; Mice; Non-alcoholic Fatty Liver Disease; Proglumide; Receptor, Cholecystokinin B

Temporal lobe epilepsy (TLE) is characterized by recurrent spontaneous seizures and behavioral comorbidities. Reduced hippocampal theta oscillations and hyperexcitability that contribute to cognitive deficits and spontaneous seizures are present beyond the sclerotic hippocampus in TLE. However, the mechanisms underlying compromised network oscillations and hyperexcitability observed in circuits remote from the sclerotic hippocampus are largely unknown. Cholecystokinin (CCK)-expressing basket cells (CCKBCs) critically participate in hippocampal theta rhythmogenesis, and regulate neuronal excitability. Thus, we examined whether CCKBCs were vulnerable in nonsclerotic regions of the ventral hippocampus remote from dorsal sclerotic hippocampus using the intrahippocampal kainate (IHK) mouse model of TLE, targeting unilateral dorsal hippocampus. We found a decrease in the number of CCK+ interneurons in ipsilateral ventral CA1 regions from epileptic mice compared to those from sham controls. We also found that the number of boutons from CCK+ interneurons was reduced in the stratum pyramidale, but not in other CA1 layers, of ipsilateral hippocampus in epileptic mice, suggesting that CCKBCs are vulnerable. Electrical recordings showed that synaptic connectivity and strength from surviving CCKBCs to CA1 pyramidal cells (PCs) were similar between epileptic mice and sham controls. In agreement with reduced CCKBC number in TLE, electrical recordings revealed a significant reduction in amplitude and frequency of IPSCs in CA1 PCs evoked by carbachol (commonly used to excite CCK+ interneurons) in ventral CA1 regions from epileptic mice versus sham controls. These findings suggest that loss of CCKBCs beyond the hippocampal lesion may contribute to hyperexcitability and compromised network oscillations in TLE.

Topics: Animals; CA1 Region, Hippocampal; Cholecystokinin; Disease Models, Animal; Epilepsy, Temporal Lobe; Female; GABAergic Neurons; Gene Expression; Interneurons; Kainic Acid; Male; Mice; Mice, Inbred C57BL

We have previously demonstrated that the pancreas can recover from chronic pancreatitis (CP) lesions in the cerulein-induced mouse model. To explore how pancreatic recovery is achieved at the molecular level, we used RNA-sequencing (seq) and profiled transcriptomes during CP transition to recovery. CP was induced by intraperitoneally injecting cerulein in C57BL/6 mice. Time-matched controls (CON) were given normal saline. Pancreata were harvested from mice 4 days after the final injections (designated as CP and CON) or 4 weeks after the final injections (designated as CP recovery (CPR) and control recovery (CONR)). Pancreatic RNAs were extracted for RNA-seq and quantitative (q) PCR validation. Using RNA-seq, we identified a total of 3,600 differentially expressed genes (DEGs) in CP versus CON and 166 DEGs in CPR versus CONR. There are 132 DEGs overlapped between CP and CPR and 34 DEGs unique to CPR. A number of selected pancreatic fibrosis-relevant DEGs were validated by qPCR. The top 20 gene sets enriched from DEGs shared between CP and CPR are relevant to extracellular matrix and cancer biology, whereas the top 10 gene sets enriched from DEGs specific to CPR are pertinent to DNA methylation and specific signaling pathways. In conclusion, we identified a distinct set of DEGs in association with extracellular matrix and cancer cell activities to contrast CP and CPR. Once during ongoing CP recovery, DEGs relevant to DNA methylation and specific signaling pathways were induced to express. The DEGs shared between CP and CPR and the DEGs specific to CPR may serve as the unique transcriptomic signatures and biomarkers for determining CP recovery and monitoring potential therapeutic responses at the molecular level to reflect pancreatic histological resolution.

Topics: Animals; Ceruletide; Cholecystokinin; Disease Models, Animal; Extracellular Matrix; Female; Gene Expression Profiling; Gene Expression Regulation; Male; Mice; Mice, Inbred C57BL; Pancreas; Pancreatitis, Chronic; RNA-Seq; Signal Transduction; Transcriptome

Migraine is a disabling neurovascular disorder, which increases risk of cardiovascular events and is a social burden worldwide. The present first-line anti-migraine medications can cause overwhelming side-effects, of which one includes the onset of cardiovascular disease. As one of the marketed Tibetan drugs, Ru-yi-Zhen-bao Pills (RYZBP) have been clinically used to treat cardiovascular disorders and as anti-migraine medication. However, there is currently no research exploring the anti-migraine actions of RYZBP.. The current research was designed to assess the anti-migraine roles of RYZBP and explore the underlying mechanisms in a nitroglycerin (NTG)-induced migraine rat model trial.. 120 rats were randomly divided into the following six groups of 20 rats each: normal control group, model control group, positive control group, and RYZBP high/medium/low-dose groups (Ru-yi-Zhen-bao Pills; TH 1.00 g/kg, TM 0.50 g/kg and TL 0.25 g/kg). All rats were administered intragastrically for 7 consecutive days, which were subcutaneously injected with the NTG (10 mg/kg) after the last gavage (except in the normal control group). 3min after NTG treatment, 30 rats (5 rats from each group) were anesthetized and devoted to electroencephalogram(EEG) testing, which was used to evaluate the analgesic effect of RYZBP. One hour after NTG treatment, the rest of the 90 rats (15 rats from each group) were anesthetized and midbrain tissue sample was dissected. The dissection was then washed with physiological saline and collected. The histopathological changes in the periaqueductal gray(PAG) of 5 tissue samples were determined by aematoxylin-eosin (H&E) staining, as well as an estimation of substance P (SP) and neurokinin 1 receptor (NK1R) expression through immunohistochemically staining(IHC). Another 5 midbrain preparations were carried out to evaluate calcitonin gene-related peptide (CGRP), proenkephalin (PENK), SP, and cholecystokinin (CCK) expressions by real-time quantitative polymerase chain reaction (RT-qPCR). The rest of the 5 brainstem tissues were then used to measure CCK, CGRP, and opioid peptide receptor (DORR) levels by western blotting(WB).. In the EEG test, RYZBP (TM 0.50 g / kg) treatment transformed the EEG pain-wave of the NTG-induced migraine model rats in different time period. In the mechanism assay, compared with the model control group, RYZBP pretreatment reduced inflammatory cell infiltration, fibrosis and vacuolation of neuronal cells of PAG tissue seen by HE staining. IHC experiments further showed that RYZBPTM up-regulated SP expression levels and enhanced NK1R levels in the NTG-induced migraine rats (P < 0.05). Therapeutic administration of RYZBP also increased PENK mRNA expression and DORR protein level. Both RT-qPCR and western blotting trials indicated that RYZBP treatment significantly decreased CCK and CGRP expression levels (P < 0.01 or P < 0.05) in the NTG-induced migraine rats.. RYZBP has the potential to be an effective anti-migraine treatment through suppressing the EEG pain-wave, increasing the levels of SP, PENK, DORR and reducing expression of CCK and CGRP. Mediating the PAG anti-nociceptive channel and inhibiting central sensitization were the two potential mechanisms, which offers further evidence for clinical therapy.

Topics: Animals; Calcitonin Gene-Related Peptide; Cholecystokinin; Disease Models, Animal; Drugs, Chinese Herbal; Electroencephalography; Enkephalins; Humans; Male; Medicine, Tibetan Traditional; Migraine Disorders; Nitroglycerin; Nociception; Periaqueductal Gray; Protein Precursors; Rats; Rats, Sprague-Dawley; Receptors, Opioid

Layering has been a long-appreciated feature of higher order mammalian brain structures but the extent to which it plays an instructive role in synaptic specification remains unknown. Here we examine the formation of synaptic circuitry under cellular heterotopia in hippocampal CA1, using a mouse model of the human neurodevelopmental disorder Type I Lissencephaly. We identify calbindin-expressing principal cells which are mispositioned under cellular heterotopia. Ectopic calbindin-expressing principal cells develop relatively normal morphological features and stunted intrinsic physiological features. Regarding network development, a connectivity preference for cholecystokinin-expressing interneurons to target calbindin-expressing principal cells is diminished. Moreover, in vitro gamma oscillatory activity is less synchronous across heterotopic bands and mutants are less responsive to pharmacological inhibition of cholecystokinin-containing interneurons. This study will aid not only in our understanding of how cellular networks form but highlight vulnerable cellular circuit motifs that might be generalized across disease states.

Topics: Animals; Calbindins; Cholecystokinin; Classical Lissencephalies and Subcortical Band Heterotopias; Disease Models, Animal; Female; Hippocampus; Humans; Interneurons; Male; Mice; Pyramidal Cells

Metabolic disorders can induce psychiatric comorbidities. Both brain and neuronal composition imbalances reportedly induce an anxiety-like phenotype. We hypothesized that alterations of localized brain areas and cholecystokinin (CCK) and parvalbumin (PV) expression could induce anxiety-like behavior in type 2 diabetic Otsuka Long-Evans Tokushima fatty (OLETF) rats. Twenty-week-old OLETF and non-diabetic Long-Evans Tokushima Otsuka (LETO) rats were used. The areas of corticolimbic regions were smaller in OLETF rats. The densities of CCK positive neurons in the lateral and basolateral amygdala, hippocampal cornu ammonis area 2, and prelimbic cortex were higher in OLETF rats. The densities of PV positive neurons were comparable between OLETF and LETO rats. Locomotion in the center zone in the open field test was lower in OLETF rats. These results suggest that imbalances of specific brain region areas and neuronal compositions in emotion-related areas increase the prevalence of anxiety-like behaviors in OLETF rats.

Topics: Animals; Anxiety; Behavior, Animal; Brain; Cholecystokinin; Diabetes Mellitus, Type 2; Disease Models, Animal; Emotions; Locomotion; Male; Neurons; Open Field Test; Parvalbumins; Rats, Inbred OLETF

Acute pancreatitis is an inflammatory process of the pancreas and a leading cause of hospitalization amongst gastrointestinal disorders. Previously, cholecystokinin (CCK) has been described to play a role in regeneration of pancreas. The aim of this study was to analyse the function of cholecystokinin octapeptide (CCK-8) during induced pancreatitis in an animal model.. Overall acute pancreatitis was induced in 38 pigs. After the induction of acute pancreatitis, half of the animals were treated with CCK-8. Intraoperative clinical data, postoperative blood parameters, 'Porcine Well-being' (PWB) and fitness score and post-mortal histopathological data were analysed.. At baseline, physiologically parameters of the pigs of both groups were comparable. No differences were observed regarding the overall survival of animals (p = 0.97). Postoperative PWB score were significantly enhanced in animals treated with CCK-8 as compared to the control group (p = 0.029). Moreover, histopathological analysis of the pancreatic tissue revealed that acinar necrosis and edema were significant reduced in the CCK-8 group in comparison to the control group (p = 0.016 and p = 0.019).. In conclusion, we found that CCK-8 treatment reduces acinar necrosis and edema of pancreatic tissue after induction of an acute pancreatitis in pigs.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Necrosis; Pancreas; Pancreatitis; Peptide Fragments; Swine

Cholecystokinin (CCK) is a regulator of appetite and energy intake in man. The aim of this study was to determine the effect of NN9056, a long-acting CCK-1 receptor-selective CCK analogue, on food intake and body weight (BW) in obese Göttingen Minipigs.. Tolerability of NN9056 and acute effects on food intake, pancreas histology, amylase and lipase levels were assessed in lean domestic pigs in doses up to 100 nmol/kg (n = 3-4). Subsequently, obese Göttingen Minipigs were treated subcutaneously (s.c.) once daily for 13 weeks with vehicle, NN9056 low dose (regulated from 5 to 2 nmol/kg) or NN9056 high dose (10 nmol/kg) (n = 7-8). Food intake was measured daily and BW twice weekly. At the end of the treatment period, an intravenous glucose tolerance test (IVGTT) and a 24-h exposure profile was obtained. Data are mean ± SD.. The acute studies in domestic pigs showed significant and dose-dependent effect of NN9056 on food intake, acceptable tolerability and no histopathological signs of pancreatitis. Sub-chronic treatment in obese Göttingen Minipigs was also well tolerated and accumulated food intake was significantly lower in both treated groups compared to vehicle, with no significant difference between the dose levels of NN9056 (41.8 ± 12.6, 51.5 ± 13.8 and 86.5 ± 19.5 kg in high-dose, low-dose and vehicle groups, respectively, p = 0.012 and p < 0.0001 for low and high dose vs. vehicle, respectively). Accordingly, there was a weight loss in both treated groups vs. a weight gain in the vehicle group (-7.2 ± 4.6%, -2.3 ± 3.2% and 12.3 ± 3.9% in the high-dose, low-dose and vehicle groups, respectively, p < 0.0001 for both vs. vehicle). IVGTT data were not significantly different between groups.. NN9056, a long-acting CCK-1 receptor-selective CCK analogue, significantly reduced food intake and BW in obese Göttingen Minipigs after once daily s.c. dosing for 13 weeks.

Topics: Animals; Body Weight; Cholecystokinin; Disease Models, Animal; Eating; Energy Intake; Female; Humans; Obesity; Protein Binding; Swine; Swine, Miniature

Pain is associated with negative emotions such as anxiety, but the underlying neurocircuitry and modulators of the association of pain and anxiety remain unclear. The neuropeptide cholecystokinin (CCK) has both pronociceptive and anxiogenic properties, so we explored the role of CCK in anxiety and nociception in the central amygdala (CeA), a key area in control of emotions and descending pain pathways. Local infusion of CCK into the CeA of control rats increased anxiety, as measured in the light-dark box test, but had no effect on mechanical sensitivity. By contrast, intra-CeA CCK infusion 4 days after Complete Freund's Adjuvant (CFA) injection into the hindpaw resulted in analgesia, but also in loss of its anxiogenic capacity. Inflammatory conditions induced changes in the CeA CCK signaling system with an increase of CCK immunoreactivity and a decrease in CCK1, but not CCK2, receptor mRNA. In CFA rats, patch-clamp experiments revealed that CCK infusion increased CeA neuron excitability. It also partially blocked the discharge of wide dynamic range neurons in the dorsal spinal cord. These effects of CCK on CeA and spinal neurons in CFA rats were mimicked by the specific CCK2 receptor agonist, gastrin. This analgesic effect was likely mediated by identified CeA neurons projecting to the periaqueductal gray matter that express CCK receptors. Together, our data demonstrate that intra-CeA CCK infusion activated a descending CCK2 receptor-dependent pathway that inhibited spinal neuron discharge. Thus, persistent pain induces a functional switch to a newly identified analgesic capacity of CCK in the amygdala, indicating central emotion-related circuit controls pain transmission in spinal cord.

Topics: Amygdala; Animals; Cholecystokinin; Dark Adaptation; Disease Models, Animal; Exploratory Behavior; Freund's Adjuvant; Gastrins; Glutamate Decarboxylase; Inflammation; Male; Neurons; Nociception; Pain; Pain Threshold; Periaqueductal Gray; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin B; Signal Transduction; Sincalide; Tetragastrin

Sleeve gastrectomy with ileal transposition has been shown to be superior to sleeve gastrectomy alone for promoting weight loss in rat and porcine models. The absence of a mouse model for this procedure has impeded efforts to understand the molecular physiology underlying its efficacy. This study demonstrates the long-term survivability of sleeve gastrectomy with ileal transposition in mice.. In this study of technical feasibility, a sleeve gastrectomy with ileal transposition (SGIT), sleeve gastrectomy (SG), or sham surgery (SH) was performed on 7- to 8-week-old C57Bl/6J mice (n = 8 for each). To evaluate long-term survivability, mice were placed on an obesogenic diet and weighed weekly for 10 weeks. The intestinal identity of the transposed segment was assessed with gene expression analysis of duodenal-, jejunal-, and ileal-specific hormones using quantitative polymerase chain reaction.. Overall, SGIT better prevented weight gain than the SG or sham procedures (10-week post-operative weight: SH 45.3 ± 1.0 g, SG 41.25 ± 1.6 g, SGIT 35.4 ± 0.8 g). Gene expression pattern analysis of three markers of intestinal identity (gastrin, cholecystokinin, and peptide YY) suggests that the ileal identity of the transposed segment is maintained 10 weeks after transposition.. We demonstrate for the first time a reproducible mouse model of sleeve gastrectomy with ileal transposition. Future studies utilizing this model will expand our understanding of the molecular pathways through which the hindgut regulates satiety.

Topics: Animals; Biomarkers; Blood Glucose; Cholecystokinin; Disease Models, Animal; Feasibility Studies; Gastrectomy; Gastrins; Gene Expression; Ileum; Mice, Inbred C57BL; Peptide YY; Random Allocation; RNA; Weight Loss

HA modified by bisphosphonate (BP) (HA-BP) was synthesized by chemical reaction and possessed promising properties such as self-healing, injection ability, and strong adhesion. The main aim of this study was to confirm its role in promoting osteogenic differentiation in vitro and bone regeneration in vivo.. The cell biocompatibility of this material was determined using the CCK-8 assay. Alkaline phosphatase (ALP), osteocalcin (OT), vascular endothelial growth factor (VEGF), and collagen I were assessed by quantitative real-time polymerase chain reaction (Q-PCR) in the treated group. The number and density of calcium nodules and ALP were evaluated by Alizarin Red staining and ALP staining. We have successfully developed an animal model simulating osteonecrosis of the femoral head (ONFH). Utilizing this animal model, the impact of HA-BP/CaP on bone formation was assessed. The amount of bone regeneration at 1 and 2 months after HA-BP/CaP injection was estimated by micro-computed tomography (micro-CT) analysis and H&E, collagen I, and periostin staining.. The number of cells gradually increased in the experimental group over time and was close to that of the blank control group. ALP, collagen I, and VEGF expression was significantly higher in the experimental group than in the blank group (VEGF, ALP, both **p < 0.01; collagen I, ***p<0.001). In addition, the number and density of calcium nodules and ALP was clearly greater in the material group than in the control group. The quantification analysis showed that the mineral contents of regenerated bone at 1 and 2 months after HA-BP/CaP injection were significantly greater than those in the control group, according to micro-CT evaluation (**p<0.01). The amount of organic components in the HA-BP/CaP group was greater than that in the control group after decalcification and H&E staining. In addition, collagen I and periostin staining further confirmed the results of H&E staining.. This material can boost proliferation and osteogenic differentiation of MC3T3-E1 cells in vitro. It can intensely accelerate bone regeneration in vivo, which is a promising strategy for tissue engineering.

Topics: 3T3 Cells; Animals; Biocompatible Materials; Bone Regeneration; Calcium Phosphates; Cell Differentiation; Cell Proliferation; Cholecystokinin; Diphosphonates; Disease Models, Animal; Female; Femur Head Necrosis; Humans; Hyaluronic Acid; Hydrogels; Materials Testing; Mice; Osteogenesis; Peptide Fragments; Rabbits; Tissue Engineering; X-Ray Microtomography

The satiety effects and metabolic actions of cholecystokinin (CCK) have been recognized as potential therapeutic targets in obesity for decades. We identified a potentially novel Ca2+-activated chloride (Cl-) current (CaCC) that is induced by CCK in intestinal vagal afferents of nodose neurons. The CaCC subunit Anoctamin 2 (Ano2/TMEM16B) is the dominant contributor to this current. Its expression is reduced, as is CCK current activity in obese mice on a high-fat diet (HFD). Reduced expression of TMEM16B in the heterozygote KO of the channel in sensory neurons results in an obese phenotype with a loss of CCK sensitivity in intestinal nodose neurons, a loss of CCK-induced satiety, and metabolic changes, including decreased energy expenditure. The effect on energy expenditure is further supported by evidence in rats showing that CCK enhances sympathetic nerve activity and thermogenesis in brown adipose tissue, and these effects are abrogated by a HFD and vagotomy. Our findings reveal that Ano2/TMEM16B is a Ca2+-activated chloride channel in vagal afferents of nodose neurons and a major determinant of CCK-induced satiety, body weight control, and energy expenditure, making it a potential therapeutic target in obesity.

Topics: Adipose Tissue, Brown; Animals; Anoctamins; Cholecystokinin; Diet, High-Fat; Disease Models, Animal; Intestines; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; Obesity; Rats; Sensory Receptor Cells; Transcriptome; Vagus Nerve

Cholecystokinin (CCK) is one of the main neurohormone peptide systems in the brain, and a major anxiogenic mediator. The periaqueductal gray (PAG) is a key midbrain structure for defensive behaviors, which could include anxiety, fear, or even panic. The CCK system has wide distribution in the PAG, where the dorsolateral region (DL) participates in active defensive behavior and the ventrolateral region (VL) in passive defensive behavior. The aim of this study was to assess the effect of CCK-8 microinjection into DL-PAG or VL-PAG on anxiety-like behavior through two tests: elevated plus maze (EPM) and defensive burying behavior (DBB). CCK-8 (0.5 and 1.0 μg/0.5 μL) presently microinjected into the DL-PAG produced an anxiogenic-like effect on the EPM evidenced by decreasing the time spent/number of entries in open arms compared to vehicle group. Additionally, the latency to burying decreased and burying time increased on the DBB test. Contrarily, CCK-8 microinjected into the VL-PAG resulted in greater open-arm time and more open-arm entries compared to the vehicle-microinjected group. The results on the DBB test confirmed an anxiolytic-like response of CCK-8 into the VL-PAG. In conclusion, CCK-8 microinjected into DL-PAG produced anxiety-like behavior on EPM, and for first time reported on DBB. Contrarily, CCK-8 microinjected into the VL-PAG reduced anxiety-like behavior also for first time reported using both behavioral models EPM and DBB.

Topics: Animals; Anti-Anxiety Agents; Anxiety; Behavior, Animal; Cholecystokinin; Disease Models, Animal; Escape Reaction; Fear; Injections, Intraventricular; Male; Maze Learning; Microinjections; Periaqueductal Gray; Rats; Rats, Wistar; Sincalide

The Sonic hedgehog (Shh) signaling pathway is recapitulated in response to ischemic injury. Here, we investigated the clinical implications of Shh protein in the ischemic stroke and explored the underlying mechanism. Intracerebroventricular injection of Shh, Cyclopamine, or anti-vascular endothelial growth factor (VEGF) was performed immediately after permanent middle cerebral artery occlusion (pMCAO) surgery and lasted for 7days (d). Phosphate-buffered saline (PBS) was used as control. Neurological deficits and infarct volume were examined 7d after pMCAO. Microvascular density with fluorescein-iso-thiocyanate (FITC) assay and double staining with CD31 and Ki-67 was measured at 7d. To observe in vitro angiogenesis, rat brain microvascular endothelial cells (RBMECs) were incubated under oxygen glucose deprivation (OGD) for 6h (h) and treated with Shh/anti-VEGF. We found that (1) Shh improved neurological scores and reduced infarct volume, which was blocked by Cyclopamine, (2) Shh improved the microvascular density and promoted angiogenesis and neuron survival in the ischemic boundary zone, (3) Shh enhanced VEGF expression and VEGF antibody could reverse angiogenic and protective effect of Shh in vivo and in vitro. These data demonstrate that the administration of Shh protein could protect brain from ischemic injury, in part by promoting angiogenic repair.

Topics: Angiogenesis Inducing Agents; Animals; Brain; Brain Infarction; Cell Movement; Cells, Cultured; Cholecystokinin; Disease Models, Animal; Drug Delivery Systems; Dyneins; Endothelial Cells; Hedgehog Proteins; Male; Neovascularization, Pathologic; Patched-1 Receptor; Peptide Fragments; Rats; Rats, Sprague-Dawley; Signal Transduction; Stroke; Vascular Endothelial Growth Factor A

Membrane proteins are targets of most available pharmaceuticals, but they are difficult to produce recombinantly, like many other aggregation-prone proteins. Spiders can produce silk proteins at huge concentrations by sequestering their aggregation-prone regions in micellar structures, where the very soluble N-terminal domain (NT) forms the shell. We hypothesize that fusion to NT could similarly solubilize non-spidroin proteins, and design a charge-reversed mutant (NT*) that is pH insensitive, stabilized and hypersoluble compared to wild-type NT. NT*-transmembrane protein fusions yield up to eight times more of soluble protein in Escherichia coli than fusions with several conventional tags. NT* enables transmembrane peptide purification to homogeneity without chromatography and manufacture of low-cost synthetic lung surfactant that works in an animal model of respiratory disease. NT* also allows efficient expression and purification of non-transmembrane proteins, which are otherwise refractory to recombinant production, and offers a new tool for reluctant proteins in general.

Topics: Animals; Cholecystokinin; Chromatography; Circular Dichroism; Dimerization; Disease Models, Animal; Escherichia coli; Female; Fibroins; Hydrogen-Ion Concentration; Lung; Magnetic Resonance Spectroscopy; Micelles; Microscopy, Electron, Transmission; Mutagenesis, Site-Directed; Mutation; Peptides; Protein Domains; Rabbits; Recombinant Proteins; Respiration Disorders; Silk; Spiders; Surface-Active Agents

The sites of action regulating meal size (MS) and intermeal interval (IMI) length by glucagon like peptide-1 (7-36) (GLP-1 (7-36)) and cholecystokinin-8 (CCK-8) reside in the areas supplied by the two major branches of the abdominal aorta, celiac and cranial mesenteric arteries. We hypothesized that infusing GLP-1 near those sites reduces body weight (BW) and adding CCK-8 to this infusion enhances the reduction. Here, we measured BW in diet-induced obese (DIO) male rats maintained and tested on normal rat chow and infused with saline, GLP-1 (0.5nmol/kg) and GLP-1+CCK-8 (0.5nmol/kg each) in the aorta once daily for 21days. We found that GLP-1 and GLP-1+CCK-8 decrease BW relative to saline vehicle and GLP-1+CCK-8 reduced it more than GLP-1 alone. Reduction of BW by GLP-1 alone was accompanied by decreased 24-h food intake, first MS, duration of first meal and number of meals, and an increase in latency to first meal. Reduction of BW by the combination of the peptides was accompanied by decrease 24-h food intake, first MS, duration of first meal and number of meals, and increase in the IMI length, satiety ratio and latency to first meal. In conclusion, GLP-1 reduces BW and CCK-8 enhances this reduction if the peptides are given near their sites of action.

Topics: Animals; Anti-Obesity Agents; Aorta; Cholecystokinin; Diet, High-Fat; Disease Models, Animal; Drug Therapy, Combination; Eating; Feeding Behavior; Glucagon-Like Peptide 1; Male; Obesity; Peptide Fragments; Rats, Sprague-Dawley; Satiation; Time Factors; Weight Loss

Topics: Animals; Anorexia; Appetite Regulation; Behavior, Animal; Cholecystokinin; Disease Models, Animal; Feeding Behavior; Female; Glucagon-Like Peptide 1; Mice; Peptide Fragments; Satiety Response; Signal Transduction; T-2 Toxin; Time Factors; Trichothecenes; Up-Regulation

Cholecystokinin (CCK) is expressed in cardiomyocytes and may also play an important role in cardiovascular regulation. Clinical studies have shown that plasma CCK levels are an independent marker of cardiovascular mortality in cardiac disease. However, whether the development of postinfarction heart failure is associated with changes in CCK expression is unknown.. To investigate CCK expression patterns and the association between CCK expression and heart functional parameters, we randomized male Sprague-Dawley rats into myocardial infarction (MI) or sham operation (SO) groups. CCK expression levels were assessed by western blotting, immunohistochemistry, real-time polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) at different time points (2, 4 or 6 weeks) after surgery. Brain natriuretic peptide (BNP) concentrations were determined using Western blotting and ELISA, myocardial morphology was assessed by microscopy.. Plasma CCK and BNP levels were significantly increased in all the MI groups compared with the corresponding SO groups. However, the degree to which myocardial CCK mRNA and protein expression levels were increased the MI groups compared with the SO groups was greater in the 4- and 6-week groups than in the 2-week group. Furthermore, plasma CCK levels were positively correlated with BNP concentrations and left ventricular end-systolic diameter (LVDs) and significantly negatively correlated with the ejection fraction (EF) and shortening fraction (SF) in model animals.. Heart failure progression after infarction is associated with upregulated CCK levels; thus, CCK may be useful as a novel marker of heart failure.

Topics: Animals; Biomarkers; Body Weight; Cholecystokinin; Disease Models, Animal; Echocardiography; Enzyme-Linked Immunosorbent Assay; Fibrosis; Heart; Heart Failure; Immunohistochemistry; Male; Myocardial Infarction; Myocardium; Natriuretic Peptide, Brain; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction

Cortical GABAergic dysfunctions have been documented by clinical studies in major depression. We used here an animal model for depression and investigated whether long-term stress exposure can affect the number of GABAergic neurons in the orbitofrontal cortex (OFC). Adult male rats were subjected to 7-weeks of daily stress exposure and behaviorally phenotyped as anhedonic or stress-resilient animals. GABAergic interneurons were identified by immunohistochemistry and systematically quantified. We analyzed calbindin-(CB), calretinin-(CR), cholecystokinin-(CCK), parvalbumin-(PV), neuropeptide Y-(NPY) and somatostatin-positive (SST+) neurons in the following specific subareas of the OFC: medial orbital (MO), ventral orbital (VO), lateral orbital (LO) and dorsolateral orbital (DLO) cortex. For comparison, we also analyzed the primary motor cortex (M1) as a non-limbic cortical area. Stress had a pronounced effect on CB+ neurons and reduced their densities by 40-50% in the MO, VO and DLO. Stress had no effect on CCK+, CR+, PV+, NPY+ and SST+ neurons in any cortical areas. None of the investigated GABAergic neurons were affected by stress in the primary motor cortex. Interestingly, in the stress-resilient animals, we observed a significantly increased density of CCK+ neurons in the VO. NPY+ neuron densities were also significantly different between the anhedonic and stress-resilient rats, but only in the LO. Our present data demonstrate that chronic stress can specifically reduce the density of calbindin-positive GABAergic neurons in the orbitofrontal cortex and suggest that NPY and CCK expression in the OFC may relate to the stress resilience of the animals.

Topics: Animals; Calbindin 2; Calbindins; Cell Count; Cholecystokinin; Depression; Disease Models, Animal; Food Preferences; GABAergic Neurons; Gene Expression Regulation; Male; Neuropeptide Y; Parvalbumins; Prefrontal Cortex; Rats; Rats, Wistar; Somatostatin; Stress, Psychological; Sucrose

Stress can alter the number and morphology of excitatory synapses in the hippocampus, but nothing is known about the effect of stress on inhibitory synapses. Here, we used an animal model for depression, the chronic mild stress model, and quantified the number of perisomatic inhibitory neurons and their synapses. We found reduced density of parvalbumin-positive (PV+) neurons in response to stress, while the density of cholecystokinin-immunoreactive (CCK+) neurons was unaffected. We did a detailed electron microscopic analysis to quantify the frequency and morphology of perisomatic inhibitory synapses in the hippocampal CA1 area. We analyzed 1100 CA1 pyramidal neurons and 4800 perisomatic terminals in five control and four chronically stressed rats. In the control animals we observed the following parameters: Number of terminals/soma = 57; Number of terminals/100 µm cell perimeter = 10; Synapse/terminal ratio = 32%; Synapse number/100 terminal = 120; Average terminal length = 920nm. None of these parameters were affected by the stress exposure. Overall, these data indicate that despite the depressive-like behavior and the decrease in the number of perisomatic PV+ neurons in the light microscopic preparations, the number of perisomatic inhibitory synapses on CA1 pyramidal cells was not affected by stress. In the electron microscope, PV+ neurons and the axon terminals appeared to be normal and we did not find any apoptotic or necrotic cells. This data is in sharp contrast to the remarkable remodeling of the excitatory synapses on spines that has been reported in response to stress and depressive-like behavior. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc.

Topics: Animals; CA1 Region, Hippocampal; Cell Count; Cholecystokinin; Depressive Disorder; Disease Models, Animal; Immunohistochemistry; Male; Microscopy, Electron; Neural Inhibition; Parvalbumins; Presynaptic Terminals; Pyramidal Cells; Rats, Wistar; Stress, Psychological; Synapses

Consumption of sugar-sweetened beverages is associated with overweight and obesity. In this study, we hypothesized that obesity-prone (OP) mice fed a high-fat high-sucrose diet (HFHS) are more sensitive to consumption of sucrose-sweetened water (SSW) than obesity-resistant (OR) mice. After 3weeks of ad libitum access to the HFHS diet (7.5h/day), 180 male mice were classified as either OP (upper quartile of body weight gain, 5.2±0.1g, n=45) or OR (lower quartile, 3.2±0.1g, n=45). OP and OR mice were subsequently divided into 3 subgroups that had access to HFHS (7.5h/day) for 16weeks, supplemented with: i) water (OP/water and OR/water); ii) water and SSW (12.6% w/v), available for 2h/day randomly when access to HFHS was available and for 5 randomly-chosen days/week (OP/SSW and OR/SSW); or iii) water and SSW for 8weeks, then only water for 8weeks (OP/SSW-water and OR/SSW-water). OR/SSW mice decreased their food intake compared to OR/water mice, while OP/SSW mice exhibited an increase in food and total energy intake compared to OP/water mice. OP/SSW mice also gained more body weight and fat mass than OP/water mice, showed an increase in liver triglycerides and developed insulin resistance. These effects were fully reversed in OP/SSW-water mice. In the gut, OR/SSW mice, but not OP/SSW mice, had an increase GLP-1 and CCK response to a liquid meal compared to mice drinking only water. OP/SSW mice had a decreased expression of melanocortin receptor 4 in the hypothalamus and increased expression of delta opioid receptor in the nucleus accumbens compared to OP/water mice when fasted that could explain the hyperphagia in these mice. When access to the sucrose solution was removed for 8weeks, OP mice had increased dopaminergic and opioidergic response to a sucrose solution. Thus, intermittent access to a sucrose solution in mice fed a HFHS diet induces changes in the gut and brain signaling, leading to increased energy intake and adverse metabolic consequences only in mice prone to HFHS-induced obesity.

Topics: Animals; Body Composition; Body Weight; Cholecystokinin; Diet, High-Fat; Disease Models, Animal; Drinking; Eating; Energy Metabolism; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperphagia; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Sucrose; Sweetening Agents

The medial entorhinal cortex layer II (MEClayerII ) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII . However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII . However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII . Taken together, these findings advance our knowledge about the organization of perisomatic inhibition both in control and in epileptic animals. © 2015 Wiley Periodicals, Inc.

Topics: Animals; Calbindins; Cell Adhesion Molecules, Neuronal; Cholecystokinin; Disease Models, Animal; Entorhinal Cortex; Epilepsy, Temporal Lobe; Extracellular Matrix Proteins; Female; gamma-Aminobutyric Acid; Inhibitory Postsynaptic Potentials; Interneurons; Kainic Acid; Male; Miniature Postsynaptic Potentials; Nerve Tissue Proteins; Neural Pathways; Parvalbumins; Presynaptic Terminals; Rats, Wistar; Reelin Protein; Serine Endopeptidases; Tissue Culture Techniques

Oxytocin (OT) is a neuropeptide elaborated by the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Magnocellular OT neurons of these nuclei innervate numerous forebrain regions and release OT into the blood from the posterior pituitary. The PVN also harbors parvocellular OT cells that project to the brainstem and spinal cord, but their function has not been directly assessed. Here, we identified a subset of approximately 30 parvocellular OT neurons, with collateral projections onto magnocellular OT neurons and neurons of deep layers of the spinal cord. Evoked OT release from these OT neurons suppresses nociception and promotes analgesia in an animal model of inflammatory pain. Our findings identify a new population of OT neurons that modulates nociception in a two tier process: (1) directly by release of OT from axons onto sensory spinal cord neurons and inhibiting their activity and (2) indirectly by stimulating OT release from SON neurons into the periphery.

Topics: Action Potentials; Animals; Cholecystokinin; Disease Models, Animal; Excitatory Amino Acid Antagonists; Gene Expression Regulation; Inflammation; Neural Pathways; Neuralgia; Neurons; Oxytocin; Paraventricular Hypothalamic Nucleus; Quinoxalines; Rats; Rats, Wistar; Receptors, Oxytocin; Spinal Cord; Supraoptic Nucleus; Transduction, Genetic; Vasopressins; Vesicular Glutamate Transport Protein 2

SCA1, a fatal neurodegenerative disorder, is caused by a CAG expansion encoding a polyglutamine stretch in the protein ATXN1. We used RNA sequencing to profile cerebellar gene expression in Pcp2-ATXN1[82Q] mice with ataxia and progressive pathology and Pcp2-ATXN1[30Q]D776 animals having ataxia in absence of Purkinje cell progressive pathology. Weighted Gene Coexpression Network Analysis of the cerebellar expression data revealed two gene networks that significantly correlated with disease and have an expression profile correlating with disease progression in ATXN1[82Q] Purkinje cells. The Magenta Module provides a signature of suppressed transcriptional programs reflecting disease progression in Purkinje cells, while the Lt Yellow Module reflects transcriptional programs activated in response to disease in Purkinje cells as well as other cerebellar cell types. Furthermore, we found that upregulation of cholecystokinin (Cck) and subsequent interaction with the Cck1 receptor likely underlies the lack of progressive Purkinje cell pathology in Pcp2-ATXN1[30Q]D776 mice.

Topics: Animals; Ataxin-1; Cerebellum; Chemokines, CC; Cholecystokinin; Disease Models, Animal; Disease Progression; Gene Regulatory Networks; Guanine Nucleotide Exchange Factors; Mice; Mice, Inbred C57BL; Mice, Transgenic; Nerve Tissue Proteins; Neuropeptides; Nuclear Proteins; Peptides; Purkinje Cells; Receptor, Cholecystokinin B; Spinocerebellar Ataxias; Transcriptome; Up-Regulation

Reduced hippocampal GABAergic inhibition is acknowledged to be associated with epilepsy. However, there are no studies that had quantitatively compared the loss of various interneuron populations in different models of epilepsy. We tested a hypothesis that the more severe the loss of hippocampal interneurons, the more severe was the epilepsy. Epileptogenesis was triggered in adult rats by status epilepticus (SE) (56 SE, 24 controls) or by traumatic brain injury (TBI) (45 TBI, 23 controls). The total number of hippocampal parvalbumin (PARV), cholecystokinin (CCK), calretinin (CR), somatostatin (SOM), or neuropeptide Y (NPY) positive neurons was estimated using unbiased stereology at 1 or 6 months post-insult. The rats with TBI had no spontaneous seizures but showed increased seizure susceptibility. Eleven of the 28 rats (39 %) in the SE group had spontaneous seizures. The most affected hippocampal area after TBI was the ipsilateral dentate gyrus, where 62 % of PARV-immunoreactive (ir) (p < 0.001 compared to controls), 77 % of CR-ir (p < 0.05), 46 % of SOM-ir (p < 0.001), and 59 % of NPY-ir (p < 0.001) cells remained at 1 month after TBI. At 6 months post-TBI, only 35 % of PARV-ir (p < 0.001 compared to controls), 63 % of CCK-ir (p < 0.01), 74 % of CR-ir (p < 0.001), 55 % of SOM-ir (p < 0.001), and 51 % of NPY-ir (p < 0.001) cells were remaining. Moreover, the reduction in PARV-ir, CCK-ir, and CR-ir neurons was bilateral (all p < 0.05). Substantial reductions in different neuronal populations were also found in subfields of the CA3 and CA1. In rats with epilepsy after SE, the number of PARV-ir neurons was reduced in the ipsilateral CA1 (80 % remaining, p < 0.05) and the number of NPY-ir neurons bilaterally in the dentate gyrus (33-37 %, p < 0.01) and the CA3 (54-57 %, p < 0.05). Taken together, interneuron loss was substantially more severe, widespread, progressive, and included more interneuron subclasses after TBI than after SE. Interneurons responsible for perisomatic inhibition were more vulnerable to TBI than those providing dendritic inhibition. Unlike expected, we could not demonstrate any etiology-independent link between the severity of hippocampal interneuron loss and the overall risk of spontaneous seizures.

Topics: Animals; Brain Injuries; Brain Waves; Calbindin 2; Cell Death; Cholecystokinin; Convulsants; Disease Models, Animal; Electrodes, Implanted; Hippocampus; Interneurons; Male; Neuropeptide Y; Parvalbumins; Pentylenetetrazole; Rats; Rats, Sprague-Dawley; Somatostatin; Status Epilepticus

Severe congenital diarrhea occurs in approximately half of patients with Aristaless-Related Homeobox (ARX) null mutations. The cause of this diarrhea is unknown. In a mouse model of intestinal Arx deficiency, the prevalence of a subset of enteroendocrine cells is altered, leading to diarrhea. Because polyalanine expansions within the ARX protein are the most common mutations found in ARX-related disorders, we sought to characterize the enteroendocrine population in human tissue of an ARX mutation and in a mouse model of the corresponding polyalanine expansion (Arx).. Immunohistochemistry and quantitative real-time polymerase chain reaction were the primary modalities used to characterize the enteroendocrine populations. Daily weights were determined for the growth curves, and Oil-Red-O staining on stool and tissue identified neutral fats.. An expansion of 7 alanines in the first polyalanine tract of both human ARX and mouse Arx altered enteroendocrine differentiation. In human tissue, cholecystokinin, glucagon-like peptide 1, and somatostatin populations were reduced, whereas the chromogranin A population was unchanged. In the mouse model, cholecystokinin and glucagon-like peptide 1 populations were also lost, although the somatostatin-expressing population was increased. The ARX protein was present in human tissue, whereas the Arx protein was degraded in the mouse intestine.. ARX/Arx is required for the specification of a subset of enteroendocrine cells in both humans and mice. Owing to protein degradation, the Arx mouse recapitulates findings of the intestinal Arx null model, but is not able to further the study of the differential effects of the ARX protein on its transcriptional targets in the intestine.

Topics: Adolescent; Animals; Cell Differentiation; Cholecystokinin; Chromogranin A; Diarrhea; Disease Models, Animal; Duodenal Diseases; Duodenum; Enteroendocrine Cells; Failure to Thrive; Female; Glucagon-Like Peptide 1; Homeodomain Proteins; Humans; Intestinal Pseudo-Obstruction; Male; Mice; Mice, Inbred C57BL; Mutagenesis, Insertional; Peptides; Somatostatin; Steatorrhea; Transcription Factors

Major depressive disorder is a common and complex mental disorder with unknown etiology. GABAergic dysfunction is likely to contribute to the pathophysiology since disrupted GABAergic systems are well documented in depressed patients. Here we studied structural changes in the hippocampal GABAergic network using the chronic mild stress (CMS) model, as one of the best validated animal models for depression. Rats were subjected to 9 weeks of daily stress and behaviorally characterized using the sucrose consumption test into anhedonic and resilient animals based on their response to stress. Different subtypes of GABAergic interneurons were visualized by immunohistochemistry using antibodies for parvalbumin (PV), calretinin (CR), calbindin (CB), cholecystokinin (CCK), somatostatin (SOM), and neuropeptide Y (NPY). We used an unbiased quantification method to systematically count labeled cells in different subareas of the dorsal and ventral hippocampus. Chronic stress reduced the number of specific interneurons in distinct hippocampal subregions significantly. PV+ and CR+ neurons were reduced in all dorsal subareas, whereas in the ventral part only the CA1 was affected. Stress had the most pronounced effect on the NPY+ and SOM+ cells and reduced their number in almost all dorsal and ventral subareas. Stress had no effect on the CCK+ and CB+ interneurons. In most cases the effect of stress was irrespective to the behavioral phenotype. However, in a few specific areas the number of SOM+, NPY+, and CR+ neurons were significantly reduced in anhedonic animals compared to the resilient group. Overall, these data clearly demonstrate that chronic stress affects the structural integrity of specific GABAergic neuronal subpopulations and this should also affect the functioning of these hippocampal GABAergic networks.

Topics: Analysis of Variance; Animals; Calbindin 1; Cell Count; Cholecystokinin; Disease Models, Animal; Food Preferences; GABAergic Neurons; Hippocampus; Interneurons; Male; Nerve Tissue Proteins; Peptide Fragments; Rats; Rats, Wistar; Stress, Psychological; Sucrose; Sweetening Agents

We have previously demonstrated that a number of rats fed a moderately high-fat diet (MHFD) become obese and hypertensive and had compromised sympathoinhibitory and vasodilator responses to the gut hormones cholecystokinin (CCK) and gastric leptin. This has implications for increased resistance in vascular beds that attract a large proportion of cardiac output after a meal and may be an important mechanism underlying the development of hypertension in obesity in which food consumption is greatly increased. The aim of this study was to determine whether swapping a MHFD for a low-fat diet (LFD) would induce weight loss in obese animals, reverse the signs of hypertension and restore sympathoinhibitory reflexes. Male Sprague-Dawley rats were placed on a LFD (controls; n = 8) or a MHFD (n = 24) for 11 weeks after which the latter displayed either an obesity-prone (OP) or obesity-resistant (OR) phenotype. All animals were fed a LFD for a further 6 weeks after which they were anaesthetised with isoflurane and artificially ventilated for evaluation of resting arterial pressure (AP) and renal sympathetic nerve responses to CCK (0.1-4 μg/kg) and leptin (15 μg/kg). Weight gain in OP animals remained higher than OR or controls following diet switch (P < 0.05 for both). Resting AP was not significantly different between OP (103 ± 4 mmHg), OR (102 ± 3 mmHg) or control (104 ± 3 mmHg) animals and sympathoinhibitory responses to CCK or leptin were not different between the groups (P > 0.05). These results demonstrate that diet modification can have beneficial effects on sympathetic function and restore normotension without the need for weight reduction.

Topics: Animals; Arterial Pressure; Autonomic Agents; Body Weight; Cholecystokinin; Diet, Fat-Restricted; Diet, High-Fat; Disease Models, Animal; Gastrointestinal Agents; Genetic Predisposition to Disease; Hypertension; Leptin; Male; Obesity; Rats, Sprague-Dawley; Sympathetic Nervous System

Although oxidative stress has been strongly implicated in the development of acute pancreatitis (AP), antioxidant therapy in patients has so far been discouraging. The aim of this study was to assess potential protective effects of a mitochondria-targeted antioxidant, MitoQ, in experimental AP using in vitro and in vivo approaches. MitoQ blocked H2O2-induced intracellular ROS responses in murine pancreatic acinar cells, an action not shared by the control analogue dTPP. MitoQ did not reduce mitochondrial depolarisation induced by either cholecystokinin (CCK) or bile acid TLCS, and at 10 µM caused depolarisation per se. Both MitoQ and dTPP increased basal and CCK-induced cell death in a plate-reader assay. In a TLCS-induced AP model MitoQ treatment was not protective. In AP induced by caerulein hyperstimulation (CER-AP), MitoQ exerted mixed effects. Thus, partial amelioration of histopathology scores was observed, actions shared by dTPP, but without reduction of the biochemical markers pancreatic trypsin or serum amylase. Interestingly, lung myeloperoxidase and interleukin-6 were concurrently increased by MitoQ in CER-AP. MitoQ caused biphasic effects on ROS production in isolated polymorphonuclear leukocytes, inhibiting an acute increase but elevating later levels. Our results suggest that MitoQ would be inappropriate for AP therapy, consistent with prior antioxidant evaluations in this disease.

Topics: Acinar Cells; Acute Disease; Animals; Antioxidants; Apoptosis; Ceruletide; Cholecystokinin; Disease Models, Animal; Inflammation; Male; Membrane Potential, Mitochondrial; Mice; Mitochondria; Necrosis; Organophosphorus Compounds; Oxidative Stress; Pancreas; Pancreatitis; Reactive Oxygen Species; Taurolithocholic Acid; Ubiquinone

To examine the effects of pancreatic rest, stimulation and rest/stimulation on the natural course of recovery after acute pancreatitis.. Acute hemorrhagic pancreatitis (AP) was induced in male rats by intraductal infusion of 40 μL/100 g body weight of 3% sodium taurocholate. All rats took food ad libitum. At 24 h after induction of AP, rats were divided into four groups: control (AP-C), pancreas rest (AP-R), stimulation (AP-S), and rest/stimulation (AP-R/S). Rats in the AP-C, AP-R and AP-S groups received oral administration of 2 mL/kg body weight saline, cholecystokinin (CCK)-1 receptor antagonist, and endogenous CCK release stimulant, respectively, twice daily for 10 d, while those in the AP-R/S group received twice daily CCK-1 receptor antagonist for the first 5 d followed by twice daily CCK release stimulant for 5 d. Rats without any treatment were used as control group (Control). Biochemical and histological changes in the pancreas, and secretory function were evaluated on day 12 at 24 h after the last treatment.. Feeding ad libitum (AP-C) delayed biochemical, histological and functional recovery from AP. In AP-C rats, bombesin-stimulated pancreatic secretory function and HOMA-β-cell score were significantly lower than those in other groups of rats. In AP-R rats, protein per DNA ratio and pancreatic exocrine secretory function were significantly low compared with those in Control rats. In AP-S and AP-R/S rats, the above parameters recovered to the Control levels. Bombesin-stimulated pancreatic exocrine response in AP-R/S rats was higher than in AP-S rats and almost returned to control levels. In the pancreas of AP-C rats, destruction of pancreatic acini, marked infiltration of inflammatory cells, and strong expression of α-smooth muscle actin, tumor necrosis factor-α and interleukin-1β were seen. Pancreatic rest reversed these histological alterations, but not atrophy of pancreatic acini and mild infiltration of inflammatory cells. In AP-S and AP-R/S rats, the pancreas showed almost normal architecture.. The favorable treatment strategy for AP is to keep the pancreas at rest during an early stage followed by pancreatic stimulation by promoting endogenous CCK release.

Topics: Administration, Oral; Animals; Biomarkers; Bombesin; Cell Proliferation; Cholecystokinin; Disease Models, Animal; DNA Replication; Esters; Gabexate; Guanidines; Hormone Antagonists; Insulin Resistance; Male; Pancreas; Pancreatic Function Tests; Pancreatitis; Proglumide; Rats, Wistar; Receptor, Cholecystokinin A; Recovery of Function; Taurocholic Acid; Time Factors

A high-altitude environment causes appetite loss in unacclimatised humans, leading to weight reduction. Ghrelin, cholecystokinin (CCK), and glucagon like peptide-1 (GLP-1), are gut hormones involved in the regulation of food intake and energy metabolism. The liver is an important site of metabolic regulation, and together with the gut it plays a role in food intake regulation. This study intends to study the time-dependent changes occurring in plasma gut hormones, PPARα, PPARδ, and PGC1α, in the stomach and liver during hypoxia.. Male Sprague Dawley rats were exposed to hypobaric hypoxia in a decompression chamber at 7620 m for different durations up to seven days.. Hypoxia increased circulating ghrelin from the third day onwards while CCK and GLP-1 decreased immediately. An increase in ghrelin, ghrelin receptor protein levels, and GOAT mRNA levels in the stomach was observed. Stomach cholecystokinin receptor (CCKAR), PPARα, and PPARδ decreased. Liver CCKAR decreased during the first day of hypoxia and returned to normal levels from the third day onwards. PPARα and PGC1α expression increased while PPARδ protein levels reduced in the liver on third day.. Hypoxia alters the expression of ghrelin and ghrelin receptor in the stomach, CCKAR in the liver, and PPAR and its cofactors, which might be possible role players in the contribution of gut and liver to anorexia at high altitude.

Topics: Animals; Anorexia; Cholecystokinin; Disease Models, Animal; Gastric Mucosa; Gene Expression Regulation; Ghrelin; Glucagon-Like Peptide 1; Hypoxia; Liver; Male; Peroxisome Proliferator-Activated Receptors; Rats; Rats, Sprague-Dawley

Inflammation triggered by necrotic acinar cells contributes to the pathophysiology of acute pancreatitis (AP), but its precise mechanism remains unclear. Recent studies have shown that Cyclophilin A (CypA) released from necrotic cells is involved in the pathogenesis of several inflammatory diseases. We therefore investigated the role of CypA in experimental AP induced by administration of sodium taurocholate (STC). CypA was markedly upregulated and widely expressed in disrupted acinar cells, infiltrated inflammatory cells, and tubular complexes. In vitro, it was released from damaged acinar cells by cholecystokinin (CCK) induction. rCypA (recombinant CypA) aggravated CCK-induced acinar cell necrosis, promoted nuclear factor (NF)-κB p65 activation, and increased cytokine production. In conclusion, CypA promotes pancreatic damage by upregulating expression of inflammatory cytokines of acinar cells via the NF-κB pathway.

Topics: Acinar Cells; Animals; Cell Death; Cholecystokinin; Cyclophilin A; Cytokines; Disease Models, Animal; Inflammation Mediators; Male; NF-kappa B; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Signal Transduction; Up-Regulation

The gut hormone cholecystokinin (CCK) acts at subdiaphragmatic vagal afferents to induce renal and splanchnic sympathoinhibition and vasodilatation, via reflex inhibition of a subclass of cardiovascular-controlling neurons in the rostroventrolateral medulla (RVLM). These sympathoinhibitory and vasodilator responses are blunted in obese, hypertensive rats and our aim in the present study was to determine whether this is attributable to (i) altered sensitivity of presympathetic vasomotor RVLM neurons, and (ii) aberrant peripheral or central signalling mechanisms. Using a diet-induced obesity model, male Sprague-Dawley rats exhibited either an obesity-prone (OP) or obesity-resistant (OR) phenotype when placed on a medium high fat diet for 13-15 weeks; control animals were placed on a low fat diet. OP animals had elevated resting arterial pressure compared to OR/control animals (P < 0.05). Barosensitivity of RVLM neurons was significantly attenuated in OP animals (P < 0.05), suggesting altered baroreflex gain. CCK induced inhibitory responses in RVLM neurons of OR/control animals but not OP animals. Subdiaphragmatic vagal nerve responsiveness to CCK and CCK1 receptor mRNA expression in nodose ganglia did not differ between the groups, but CCK induced significantly less Fos-like immunoreactivity in both the nucleus of the solitary tract and the caudal ventrolateral medulla of OP animals compared to controls (P < 0.05). These results suggest that blunted sympathoinhibitory and vasodilator responses in obesity-related hypertension are due to alterations in RVLM neuronal responses, resulting from aberrant central but not peripheral signalling mechanisms. In obesity, blunted sympathoinhibitory mechanisms may lead to increased regional vascular resistance and contribute to the development of hypertension.

Topics: Animals; Arterial Pressure; Baroreflex; Cholecystokinin; Disease Models, Animal; Hypertension; Male; Medulla Oblongata; Neural Inhibition; Nodose Ganglion; Obesity; Proto-Oncogene Proteins c-fos; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Signal Transduction; Sympathetic Nervous System

Post-traumatic stress disorder (PTSD), a debilitating psychiatric disease characterized by invasive and persistent fear memories-induced stressful experience, is associated with numerous changes in neuroendocrine function. Here, we investigated whether PTSD-like symptoms are associated with changes in the cholecystokinin (CCK) system in the basolateral amygdala. We developed an animal model of PTSD using multiple foot shocks at 1.1 mA. The resulting conditioned fear response was severe (>80% freezing) and maintained for at least 28 days. The stress-associated neurotransmitters norepinephrine, dopamine, and corticotrophin-releasing hormone were elevated at 1 day after foot shock. CCK immunoreactivity and extracellular concentration as well as the expression of CCK receptors (CCK1R, CCK2R) increased progressively for 28 days following foot shock. Taken together, these results suggest that stress-induced activation of the CCK system in the BLA, which may contribute toward the development of PTSD-like symptoms.

Topics: Amygdala; Animals; Cholecystokinin; Conditioning, Psychological; Corticotropin-Releasing Hormone; Disease Models, Animal; Dopamine; Electroshock; Extracellular Space; Fear; Foot; Freezing Reaction, Cataleptic; Male; Norepinephrine; Random Allocation; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Stress Disorders, Post-Traumatic; Time Factors

Cholecystokinin (CCK)-induced suppression of feeding is mediated by vagal sensory neurons that are destroyed by the neurotoxin capsaicin (CAP). Here we determined whether CAP-sensitive neurons mediate anorexic responses to intravenous infusions of gut hormones peptide YY-(3-36) [PYY-(3-36)] and glucagon-like peptide-1 (GLP-1). Rats received three intraperitoneal injections of CAP or vehicle (VEH) in 24 h. After recovery, non-food-deprived rats received at dark onset a 3-h intravenous infusion of CCK-8 (5, 17 pmol·kg⁻¹·min⁻¹), PYY-(3-36) (5, 17, 50 pmol·kg⁻¹·min⁻¹), or GLP-1 (17, 50 pmol·kg⁻¹·min⁻¹). CCK-8 was much less effective in reducing food intake in CAP vs. VEH rats. CCK-8 at 5 and 17 pmol·kg⁻¹·min⁻¹ reduced food intake during the 3-h infusion period by 39 and 71% in VEH rats and 7 and 18% in CAP rats. In contrast, PYY-(3-36) and GLP-1 were similarly effective in reducing food intake in VEH and CAP rats. PYY-(3-36) at 5, 17, and 50 pmol·kg⁻¹·min⁻¹ reduced food intake during the 3-h infusion period by 15, 33, and 70% in VEH rats and 13, 30, and 33% in CAP rats. GLP-1 at 17 and 50 pmol·kg⁻¹·min⁻¹ reduced food intake during the 3-h infusion period by 48 and 60% in VEH rats and 30 and 52% in CAP rats. These results suggest that anorexic responses to PYY-(3-36) and GLP-1 are not primarily mediated by the CAP-sensitive peripheral sensory neurons (presumably vagal) that mediate CCK-8-induced anorexia.

Topics: Animals; Anorexia; Behavior, Animal; Capsaicin; Cholecystokinin; Disease Models, Animal; Energy Intake; Feeding Behavior; Glucagon-Like Peptide 1; Infusions, Intravenous; Injections, Intraperitoneal; Intestinal Mucosa; Intestine, Small; Male; Neuritis; Neurons, Afferent; Peptide Fragments; Peptide YY; Rats; Vagus Nerve; Vagus Nerve Diseases

Deoxynivalenol (DON, vomitoxin), a trichothecene mycotoxin produced by Fusarium sp. that frequently occurs in cereal grains, has been associated with human and animal food poisoning. Although a common hallmark of DON-induced toxicity is the rapid onset of emesis, the mechanisms for this adverse effect are not fully understood. Recently, our laboratory has demonstrated that the mink (Neovison vison) is a suitable small animal model for investigating trichothecene-induced emesis. The goal of this study was to use this model to determine the roles of two gut satiety hormones, peptide YY3-36 (PYY3-36) and cholecystokinin (CCK), and the neurotransmitter 5-hydroxytryptamine (5-HT) in DON-induced emesis. Following ip exposure to DON at 0.1 and 0.25mg/kg bw, emesis induction ensued within 15-30min and then persisted up to 120min. Plasma DON measurement revealed that this emesis period correlated with the rapid distribution and clearance of the toxin. Significant elevations in both plasma PYY3-36 (30-60min) and 5-HT (60min) but not CCK were observed during emesis. Pretreatment with the neuropeptide Y2 receptor antagonist JNJ-31020028 attenuated DON- and PYY-induced emesis, whereas the CCK1 receptor antagonist devezapide did not alter DON's emetic effects. The 5-HT3 receptor antagonist granisetron completely suppressed induction of vomiting by DON and the 5-HT inducer cisplatin. Granisetron pretreatment also partially blocked PYY3-36-induced emesis, suggesting a potential upstream role for this gut satiety hormone in 5-HT release. Taken together, the results suggest that both PYY3-36 and 5-HT play contributory roles in DON-induced emesis.

Topics: Animals; Antiemetics; Benzamides; Cholecystokinin; Devazepide; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Granisetron; Mink; Peptide Fragments; Peptide YY; Piperazines; Serotonin; Serotonin Antagonists; Time Factors; Trichothecenes; Vomiting

Due to uncontrolled activation of digestive enzymes produced within the pancreas, acute pancreatitis is a disease with a great potential for complications and variable course. Since the pathophysiological steps of human pancreatitis can only be inadequately investigated, various animal models were established to study the course of disease. The model of supramaximal caerulein stimulation allows to gain insights into intracellular events of the early phase of acute pancreatitis. Usually, overnight fasted animals are used for the model of acute pancreatitis to achieve a maximum zymogen granula accumulation and a standardised initial situation due to diminished secretion of CCK. Furthermore, the role of the nutritional state for pathogenesis and course of acute pancreatitis is controversially discussed. The aim of the study was to investigate the impact of the nutritional status on pancreatic injury in experimental acute pancreatitis.. Using standardised supramaximal caerulein stimulation (dose: 50 µg/kg; time intervals, 1/h; max. 7×), acute oedematous interstitial pancreatitis in fasted and non-fasted mice was induced. Pancreatic injury was locally characterised by pancreatic oedema, histopathological alterations and the release of pancreatic enzyme to the serum while systemic alterations were objectified by IL-6, CRP und pulmonal MPO.. 1) Increased pancreatic serum enzyme levels after induction of acute pancreatitis in non-fasted animals do not reflect a greater affection of the pancreas since amylase and lipase in serum and pancreatic tissue correlate proportionally. The induction of acute pancreatitis provoked release of 1.3 % and 0.7 % of amylase and lipase, respectively, independently of nutritional status. 2) Neither local nor systemic parameters of pancreatic injury were significantly altered by the nutritional regimen. Pathohistologic investigations revealed increase of zymogen granula portion and cell size in non-fasted mice but no further differences compared with fasted animals. 3) During a 16-hour recovery period (no further caerulein injection), local and systemic parameters normalised.. In the relatively mild model of pancreatitis induced by hormonal hyperstimulation, there was no greater pancreatic injury despite higher intrapancreatic enzyme accumulation in non-fasted animals indicating a steady state between potentially damaging and protective factors and mechanisms.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Enzyme Precursors; Female; Humans; Male; Mice; Mice, Inbred Strains; Nutritional Status; Pancreas; Pancreatic Juice; Pancreatitis, Acute Necrotizing; Secretory Vesicles

We have previously reported that bee venom (BV) has a protective role against acute pancreatitis (AP). However, the effects of apamin, the major compound of BV, on AP have not been determined. The aim of this study was to evaluate the effects of apamin on cerulein-induced AP.. AP was induced via intraperitoneal injection of supramaximal concentrations of the stable cholecystokinin analogue cerulein (50 μg/kg) every hour for 6 times. In the apamin treatment group, apamin was administered subcutaneously (10, 50, or 100 μg/kg) at both 18 and 1 h before the first cerulein injection. The mice were sacrificed at 6 h after the final cerulein injection. Blood samples were obtained to determine serum amylase and lipase levels, as well as cytokine production. The pancreas and lung were rapidly removed for morphologic and histological examination, myeloperoxidase (MPO) assay, and real-time reverse transcription-polymerase chain reaction. Furthermore, we isolated the pancreatic acinar cells to specify the role of apamin in AP.. Pre-treatment with apamin inhibited histological damage, pancreatic weight/body weight ratio, serum level of amylase and lipase, MPO activity, and cytokine production. In addition, apamin treatment significantly inhibited cerulein-induced pancreatic acinar cell death. Furthermore, apamin treatment inhibited the cerulein-induced activation of c-Jun NH2-terminal kinases (JNK).. These results could suggest that apamin could protect against AP by inhibition of JNK activation.

Topics: Acute Disease; Animals; Apamin; Ceruletide; Cholecystokinin; Cytokines; Disease Models, Animal; Injections, Intraperitoneal; Injections, Subcutaneous; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase Kinases; NF-kappa B; Pancreas; Pancreatitis

GABA(B) receptors (GABA(B)Rs) mediate slow inhibitory effects on neuronal excitability and synaptic transmission in the brain. However, the GABA(B)R agonist baclofen can also promote excitability and seizure generation in human patients and animals models. Here we show that baclofen has concentration-dependent effects on the hippocampal network in a mouse model of mesial temporal lobe epilepsy. Application of baclofen at a high dose (10 mg/kg i.p.) reduced the power of γ oscillations and the frequency of pathological discharges in the Cornu Ammonis area 3 (CA3) area of freely moving epileptic mice. Unexpectedly, at a lower dose (1 mg/kg), baclofen markedly increased γ activity accompanied by a higher incidence of pathological discharges. Intracellular recordings from CA3 pyramidal cells in vitro further revealed that, although at a high concentration (10 µM), baclofen invariably resulted in hyperpolarization, at low concentrations (0.5 µM), the drug had divergent effects, producing depolarization and an increase in firing frequency in epileptic but not control mice. These excitatory effects were mediated by the selective muting of inhibitory cholecystokinin-positive basket cells (CCK(+) BCs), through enhanced inhibition of GABA release via presynaptic GABA(B)Rs. We conclude that cell type-specific up-regulation of GABA(B)R-mediated autoinhibition in CCK(+) BCs promotes aberrant high frequency oscillations and hyperexcitability in hippocampal networks of chronic epileptic mice.

Topics: Animals; Autoreceptors; Baclofen; CA3 Region, Hippocampal; Cholecystokinin; Disease Models, Animal; Electrophysiological Phenomena; Epilepsy, Temporal Lobe; Excitatory Amino Acid Agonists; GABA-B Receptor Agonists; Humans; Kainic Acid; Mice; Mice, Inbred C57BL; Models, Neurological; Nerve Net; Receptors, GABA-B

To determine the effect of cholecystectomy on the motility of the sphincter of Oddi (SO).. Pressures of common bile duct (CBD), SO motility and its response to bolus injections of cholecystokinin (CCK, 20 ng/kg and 100 ng/kg) were detected respectively by manometry in eight Beagle dogs before and after cholecystectomy.. After cholecystectomy the CBD pressure increased 2.18 ± 1.86 mmHg, while the cyclical motion pattern of SO still existed but with a shortened cycle duration. The basal pressure (BP), phasic contraction amplitude (PCA), phasic contraction frequency (PCF) and its mode of propagation did not change significantly. Under the stimulation of CCK after cholecystectomy, although the motion patterns of SO were similar to those before cholecystectomy, the greatest inhibitory efficacy of BP and PCA all decreased with the prolonged excitement duration and the increased percentage of retrograde contraction.. Shortly after a cholecystectomy in Beagle dogs, the CBD pressure increased, SO motilities did not change significantly during the interdigestive phase except with a shortened cycle duration. Its relaxation responded to CCK was weakened with a confused contraction pattern.

Topics: Animals; Cholagogues and Choleretics; Cholecystectomy; Cholecystokinin; Disease Models, Animal; Dogs; Gastrointestinal Motility; Manometry; Postoperative Complications; Pressure; Sphincter of Oddi; Sphincter of Oddi Dysfunction; Wound Healing

Cholecystokinin (CCK) is a rapidly degraded gastrointestinal peptide that stimulates satiety and insulin secretion. We aimed to investigate the beneficial weight-lowering and metabolic effects of the novel N-terminally modified CCK analogue, (pGlu-Gln)-CCK-8.. The biological actions of (pGlu-Gln)-CCK-8 were comprehensively evaluated in pancreatic clonal BRIN BD11 cells and in vivo in high-fat-fed and ob/ob mice.. (pGlu-Gln)-CCK-8 was completely resistant to enzymatic degradation and its satiating effects were significantly (p < 0.05 to p < 0.001) more potent than CCK-8. In BRIN-BD11 cells, (pGlu-Gln)-CCK-8 exhibited enhanced (p < 0.01 to p < 0.001) insulinotropic actions compared with CCK-8. When administered acutely to high-fat-fed or ob/ob mice, (pGlu-Gln)-CCK-8 improved glucose homeostasis. Sub-chronic twice daily injections of (pGlu-Gln)-CCK-8 in high-fat-fed mice for 28 days significantly decreased body weight (p < 0.05 to p < 0.001), accumulated food intake (p < 0.05 to p < 0.001), non-fasting glucose (p < 0.05) and triacylglycerol deposition in pancreatic (p < 0.01), adipose (p < 0.05) and liver (p < 0.001) tissue, and improved oral (p < 0.05) and i.p. (p < 0.05) glucose tolerance and insulin sensitivity (p < 0.001). Similar observations were noted in ob/ob mice given twice daily injections of (pGlu-Gln)-CCK-8. In addition, these beneficial effects were not reproduced by simple dietary restriction and were not associated with changes in energy expenditure. There was no evidence for development of tolerance to (pGlu-Gln)-CCK-8, and analysis of histology or blood-borne markers for pancreatic, liver and renal function in mice treated with (pGlu-Gln)-CCK-8 suggested little abnormal pathology.. These studies emphasise the potential of (pGlu-Gln)-CCK-8 for the alleviation of obesity and insulin resistance.

Topics: Animals; Cholecystokinin; Comorbidity; Diabetes Mellitus; Disease Models, Animal; Glucose; Homeostasis; Insulin Resistance; Male; Mice; Mice, Obese; Obesity; Sincalide

Alzheimer's disease (AD) is associated with non-cognitive symptoms such as changes in feeding behaviour that are often characterised by an increase in appetite. Increased food intake is observed in several mouse models of AD including the triple transgenic (3×TgAD) mouse, but the mechanisms underlying this hyperphagia are unknown. We therefore examined feeding behaviour in 3×TgAD mice and tested their sensitivity to exogenous and endogenous satiety factors by assessing food intake and activation of key brain regions. In the behavioural satiety sequence (BSS), 3×TgAD mice consumed more food after a fast compared to Non-Tg controls. Feeding and drinking behaviours were increased and rest decreased in 3×TgAD mice, but the overall sequence of behaviours in the BSS was maintained. Exogenous administration of the satiety factor cholecystokinin (CCK; 8-30 µg/kg, i.p.) dose-dependently reduced food intake in Non-Tg controls and increased inactive behaviour, but had no effect on food intake or behaviour in 3×TgAD mice. CCK (15 µg/kg, i.p.) increased c-Fos protein expression in the supraoptic nucleus of the hypothalamus, and the nucleus tractus solitarius (NTS) and area postrema of the brainstem to the same extent in Non-Tg and 3×TgAD mice, but less c-Fos positive cells were detected in the paraventricular hypothalamic nucleus of CCK-treated 3×TgAD compared to Non-Tg mice. In response to a fast or a period of re-feeding, there was no difference in the number of c-Fos-positive cells detected in the arcuate nucleus of the hypothalamus, NTS and area postrema of 3×TgAD compared to Non-Tg mice. The degree of c-Fos expression in the NTS was positively correlated to food intake in Non-Tg mice, however, this relationship was absent in 3×TgAD mice. These data demonstrate that 3×TgAD mice show increased feeding behaviour and insensitivity to satiation, which is possibly due to defective gut-brain signalling in response to endogenous satiety factors released by food ingestion.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Area Postrema; Cholecystokinin; Disease Models, Animal; Eating; Feeding Behavior; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Paraventricular Hypothalamic Nucleus; Presenilin-1; Proto-Oncogene Proteins c-fos; Satiation; Solitary Nucleus; Supraoptic Nucleus; tau Proteins

The transient receptor potential ankyrin 1 (TRPA1) ion channel is expressed on nociceptive primary afferent neurons. On the proximal nerve ending within the spinal dorsal horn, TRPA1 regulates transmission to spinal interneurons, and thereby pain hypersensitivity. Here we assessed whether the contribution of the spinal TRPA1 channel to pain hypersensitivity varies with the experimental pain model, properties of test stimulation or the behavioral pain response. The antihypersensitivity effect of intrathecally (i.t.) administered Chembridge-5861528 (CHEM; a selective TRPA1 channel antagonist; 5-10μg) was determined in various experimental models of pain hypersensitivity in the rat. In spinal nerve ligation and rapid eye movement (REM) sleep deprivation models, i.t. CHEM attenuated mechanical hypersensitivity. Capsaicin-induced secondary (central) but not primary (peripheral) mechanical hypersensitivity was also reduced by i.t. administration of CHEM or A-967079, another TRPA1 channel antagonist. Formalin-induced secondary mechanical hypersensitivity, but not spontaneous pain, was suppressed by i.t. CHEM. Moreover, mechanical hypersensitivity induced by cholekystokinin in the rostroventromedial medulla was attenuated by i.t. pretreatment with CHEM. Independent of the model, the antihypersensitivity effect induced by i.t. CHEM was predominant on responses evoked by low-intensity stimuli (⩽6g). CHEM (10μg i.t.) failed to attenuate pain behavior in healthy controls or mechanical hypersensitivities induced by i.t. administrations of a GABA(A) receptor antagonist, or NMDA or 5-HT(3) receptor agonists. Conversely, i.t. administration of a TRPA1 channel agonist, cinnamon aldehyde, induced mechanical hypersensitivity. The results indicate that the spinal TRPA1 channel exerts an important role in secondary (central) pain hypersensitivity to low-intensity mechanical stimulation in various pain hypersensitivity conditions. The spinal TRPA1 channel provides a promising target for the selective attenuation of a central mechanism contributing to pathophysiological pain.

Topics: Acetanilides; Analysis of Variance; Animals; Ankyrins; Calcium Channels; Capsaicin; Cholecystokinin; Cinnamomum zeylanicum; Disease Models, Animal; Dose-Response Relationship, Drug; Formaldehyde; Hyperalgesia; Male; N-Methylaspartate; Pain Measurement; Peripheral Nervous System Diseases; Purines; Rats; Rats, Wistar; Sleep Deprivation; Spinal Cord; TRPA1 Cation Channel; TRPC Cation Channels

Intrauterine growth restriction (IUGR) is associated with a substantially greater incidence of metabolic syndrome in adulthood. Animal studies have shown that IUGR offspring are hyperphagic during the early postnatal period and therefore exhibit obesity. The molecular mechanisms underlying food intake regulation in the gastrointestinal tract have not been clarified in IUGR. In the present study, we utilized a rat model of IUGR by restricting the food intake of the mother (50% of the normal intake, ad libitum; FR group) from day 7 of gestation until delivery. Pups from undernourished mothers were fostered by control mothers. We examined the food intake and assessed the gene expressions of ghrelin, peptide YY (PYY), and cholecystokinin (CCK) in the alimentary tract of male newborns (postnatal day1) and adult offspring (age, 7 months). Compared to the offspring whose mothers received the standard diet ad libitum (CON offspring), FR offspring were hyperphagic from the weaning time until the end of the experiment, and resulted in a heavier final weight. Both newborn and adult FR offspring had higher ghrelin gene expression in the stomach and higher ghrelin plasma levels than did the controls. Although the gastrointestinal gene expressions and plasma levels of the anorexic peptides, PYY and CCK, were elevated in the FR newborns, they decreased in the FR adults. Our findings suggest that the altered gene expressions of orexigenic and anorexigenic gut peptides in the gastrointestinal tract in the maternal undernutrition-induced IUGR offspring provide a potential mechanism to explain hyperphagia and obesity seen in these offspring.

Topics: Adult; Animals; Animals, Newborn; Body Weight; Cholecystokinin; Disease Models, Animal; Eating; Female; Fetal Growth Retardation; Gastrointestinal Tract; Gene Expression; Gene Expression Regulation, Developmental; Ghrelin; Humans; Hyperphagia; Male; Peptide YY; Rats; Rats, Sprague-Dawley; Up-Regulation

Xiao-Ban-Xia-Tang (XBXT), a traditional Chinese herbal medicine, has been used in China for more than 2000 years, and proved to be effective in various cases of vomiting in the clinic.. To investigate the inhibitive effect of XBXT on cisplatin-induced pica behaviour and its effective mechanism on obestatin, CCK and CGRP in the pica model of rat.. The inhibitive effect of XBXT was investigated in the pica model of rats induced by cisplatin (3mg kg(-1), i.p.) in 72h observation, the expression of obestatin in the area postrema and ileum was measured by immunohistochemistry and PCR, and the levels of CCK and CGRP in blood were measured by Elisa.. The weight of kaolin eaten in rats induced by cisplatin was significantly reduced by pretreatment with XBXT in a dose-dependent manner during the 0-24h and 24-72h periods (P<0.05). XBXT exhibited effective dose-dependent (P<0.05) inhibition on the increase of expression levels of obestatin in both the ileum and area postrema, and markedly suppressed the increase levels of CCK and CGRP in blood induced by cisplatin in a dose-dependent manner (P<0.05).. XBXT has good activity against cisplatin-induced eating kaolin in rats possibly by inhibiting central or peripheral increase of obestatin, or the levels of CCK and CGRP in blood.

Topics: Animals; Antiemetics; Antineoplastic Agents; Area Postrema; Calcitonin Gene-Related Peptide; Cholecystokinin; Cisplatin; Disease Models, Animal; Dose-Response Relationship, Drug; Down-Regulation; Drugs, Chinese Herbal; Female; Ghrelin; Ileum; Kaolin; Phytotherapy; Pica; Pinellia; Rats; Rats, Wistar; Zingiberaceae

To investigate the effect of Simotang (Decoction of Four Powered Drugs) on gastrointestinal motility, motilin and cholecystokinin expression in chronically stressed mice.. Forty mice were randomly divided into control group, stress group (model group), mosapride group and Simotang group, 10 in each group. A variety of unpredictable stimulations were used to induce chronic stress in mice. Then, the mice were treated with distilled water, mosapride or Simotang for 7 d. Gastric emptying and intestinal propulsion function were detected. Serum level of motilin was measured by enzyme-linked immunosorbent assay. Expression of cholecystokinin (CCK) in intestine, spinal cord and brain of mice was detected by immunohistochemistry and semi-quantitative reverse transcription polymerase chain reaction, respectively.. Simotang improved the gastric emptying and intestinal propulsion in chronically stressed mice. Furthermore, the serum motilin level was significantly higher and the expression levels of CCK-positive cells and genes were significantly lower in intestine, spinal cord and brain of Simotang group than in those of model group (P < 0.05). No significant difference was found in serum motilin level and expression levels of CCK-positive cells and genes between the mosapride and Simotang groups.. Simotang enhances the gastrointestinal motility in chronically stressed mice by regulating the serum motilin level and the expression of cholecystokinin.

Topics: Animals; Benzamides; Brain; Cholecystokinin; Disease Models, Animal; Drugs, Chinese Herbal; Enzyme-Linked Immunosorbent Assay; Gastrointestinal Agents; Gastrointestinal Motility; Immunohistochemistry; Intestine, Small; Male; Mice; Mice, Inbred ICR; Morpholines; Motilin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spinal Cord; Stress, Psychological

Coptis chinensis rhizomes (Coptidis Rhizoma, CR), also known as "Huang Lian", is a common component of traditional Chinese herbal formulae used for the relief of abdominal pain and diarrhea. Yet, the action mechanism of CR extract in the treatment of irritable bowel syndrome is unknown. Thus, the aim of our present study is to investigate the effect of CR extract on neonatal maternal separation (NMS)-induced visceral hyperalgesia in rats and its underlying action mechanisms.. Male Sprague-Dawley rats were subjected to 3-h daily maternal separation from postnatal day 2 to day 21 to form the NMS group. The control group consists of unseparated normal (N) rats. From day 60, rats were administrated CR (0.3, 0.8 and 1.3 g/kg) or vehicle (Veh; 0.5% carboxymethylcellulose solution) orally for 7 days for the test and control groups, respectively.. Electromyogram (EMG) signals in response to colonic distension were measured with the NMS rats showing lower pain threshold and increased EMG activity than those of the unseparated (N) rats. CR dose-dependently increased pain threshold response and attenuated EMG activity in the NMS rats. An enzymatic immunoassay study showed that CR treatment significantly reduced the serotonin (5HT) concentration from the distal colon of NMS rats compared to the Veh (control) group. Real-time quantitative PCR and Western-blotting studies showed that CR treatment substantially reduced NMS induced cholecystokinin (CCK) expression compared with the Veh group.. These results suggest that CR extract robustly reduces visceral pain that may be mediated via the mechanism of decreasing 5HT release and CCK expression in the distal colon of rats.

Topics: Abdominal Pain; Analgesics; Animals; Cholecystokinin; Colon; Coptis; Disease Models, Animal; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Electromyography; Hyperalgesia; Irritable Bowel Syndrome; Male; Maternal Deprivation; Muscle, Smooth; Pain Threshold; Phytotherapy; Rats; Rats, Sprague-Dawley; Rhizome; Serotonin; Stress, Psychological

Transcutaneous electrical nerve stimulation (TENS) is a treatment for pain that involves placement of electrical stimulation through the skin for pain relief. Previous work from our laboratory shows that repeated application of TENS produces analgesic tolerance by the fourth day and a concomitant cross-tolerance at spinal opioid receptors. Prior pharmacological studies show that blockade of cholecystokinin (CCK) receptors systemically and spinally prevents the development of analgesic tolerance to repeated doses of opioid agonists. We therefore hypothesized that systemic and intrathecal blockade of CCK receptors would prevent the development of analgesic tolerance to TENS, and cross-tolerance at spinal opioid receptors. In animals with knee joint inflammation (3% kaolin/carrageenan), high (100Hz) or low frequency (4Hz) TENS was applied daily and the mechanical withdrawal thresholds of the muscle and paw were examined. We tested thresholds before and after inflammation, and before and after TENS. Animals treated systemically, prior to TENS, with the CCK antagonist, proglumide, did not develop tolerance to repeated application of TENS on the fourth day. Spinal blockade of CCK-A or CCK-B receptors blocked the development of tolerance to high and low frequency TENS, respectively. In the same animals we show that spinal blockade of CCK-A receptors prevents cross-tolerance at spinal delta-opioid receptors that normally occurs with high frequency TENS; and blockade of CCK-B receptors prevents cross-tolerance at spinal mu-opioid receptors that normally occurs with low frequency TENS. Thus, we conclude that blockade of CCK receptors prevents the development of analgesic tolerance to repeated application of TENS in a frequency-dependent manner.

Topics: Analgesics, Opioid; Animals; Arthritis, Experimental; Benzamides; Biophysics; Carrageenan; Cholecystokinin; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Routes; Drug Tolerance; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Hyperalgesia; Kaolin; Knee Joint; Male; Pain Measurement; Pain Threshold; Piperazines; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Statistics, Nonparametric; Transcutaneous Electric Nerve Stimulation

Unilateral constrictive sciatic nerve injury (uCCI) is a common neuropathic pain model. However, the bilateral constrictive injury (bCCI) model is less well studied, and shows unique characteristics. In the present study, we sought to correlate effects of bCCI on nocifensive responses to cold and mechanical stimuli with selected dorsal horn anatomic markers. bCCI or sham ligation of both rat sciatic nerves were followed up to 90 days of behavioural testing. Additional rats sacrificed at 15, 30 and 90 days were used for anatomic analyses. Behavioural tests included hindpaw withdrawal responses to topical acetone, cold plate testing, an operant thermal preference task and hindpaw withdrawal thresholds to mechanical probing.. All nocifensive responses to cold increased and remained enhanced for >45 days. Mechanical withdrawal thresholds decreased for 25 days only. Densitometric analyses of immunoperoxidase staining in the superficial dorsal horn at L4-5 revealed decreased cholecystokinin (CCK) staining at all times after bCCI, decreased mu opiate receptor (MOR) staining, maximal at 15 days, increased neuropeptide Y (NPY) staining only at days 15 and 30, and increased neurokinin-1 receptor (NK-1R) staining at all time points, maximal at 15 days. Correlation analyses at 45 days post-bCCI, were significant for individual rat nocifensive responses in each cold test and CCK and NK-1R, but not for MOR or NPY.. These results confirm the usefulness of cold testing in bCCI rats, a new approach using CCI to model neuropathic pain, and suggest a potential value of studying the roles of dorsal horn CCK and substance P in chronic neuropathic pain. Compared to human subjects with neuropathic pain, responses to cold stimuli in rats with bCCI may be a useful model of neuropathic pain.

Topics: Acetone; Analgesics; Animals; Biomarkers; Cholecystokinin; Chronic Disease; Cold Temperature; Disease Models, Animal; Female; Functional Laterality; Hyperalgesia; Immunohistochemistry; Ligation; Neuropeptide Y; Pain Measurement; Pain Threshold; Peripheral Nervous System Diseases; Posterior Horn Cells; Predictive Value of Tests; Rats; Rats, Sprague-Dawley; Receptors, Neurokinin-1; Receptors, Opioid, mu; Reflex; Sciatic Neuropathy

Cholecystokinin (CCK) is a satiation peptide released during meals in response to lipid intake; it regulates pancreatic digestive enzymes that are required for absorption of nutrients. We proposed that mice with a disruption in the CCK gene (CCK knockout [CCK-KO] mice) that were fed a diet of 20% butter fat would have altered fat metabolism.. We used quantitative magnetic resonance imaging to determine body composition and monitored food intake of CCK-KO mice using an automated measurement system. Intestinal fat absorption and energy expenditure were determined using a noninvasive assessment of intestinal fat absorption and an open circuit calorimeter, respectively.. After consuming a high-fat diet for 10 weeks, CCK-KO mice had reduced body weight gain and body fat mass and enlarged adipocytes, despite the same level of food intake as wild-type mice. CCK-KO mice also had defects in fat absorption, especially of long-chain saturated fatty acids, but pancreatic triglyceride lipase did not appear to have a role in the fat malabsorption. Energy expenditure was higher in CCK-KO than wild-type mice, and CCK-KO mice had greater oxidation of carbohydrates while on the high-fat diet. Plasma leptin levels in the CCK-KO mice fed the high-fat diet were markedly lower than in wild-type mice, although levels of insulin, gastric-inhibitory polypeptide, and glucagon-like peptide-1 were normal.. CCK is involved in regulating the metabolic rate and is important for lipid absorption and control of body weight in mice placed on a high-fat diet.

Topics: Adiposity; Animals; Biomarkers; Butter; Calorimetry; Cholecystokinin; Dietary Fats; Disease Models, Animal; Eating; Energy Metabolism; Fatty Acids; Intestinal Absorption; Leptin; Lipase; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Motor Activity; Obesity; Time Factors; Weight Gain

Cholecystokinin (CCK) acutely synergizes with amylin to suppress food intake in lean mice. To extend on these findings, the present studies sought to identify neural correlates for the interaction of amylin and CCK, as well as further understand the therapeutic potential of CCK-based combinations in obesity. First, c-Fos activation was assessed in various brain nuclei after a single intraperitoneal injection of amylin (5microg/kg) and/or CCK (5microg/kg). Amylin and CCK additively increased c-Fos within the area postrema (AP), predominantly in noradrenergic (e.g., dopamine-beta-hydroxylase-containing) cells. Next, amylin (100 or 300microg/kg/d) and/or CCK (100 or 300microg/kg/d) were subcutaneously infused for 7days in diet-induced obese (DIO) rats. Amylin treatment of DIO rats for 7days induced significant body weight loss. CCK, while ineffective alone, significantly enhanced body weight loss when co-administered with the higher dose of amylin. Finally, the addition of CCK (300microg/kg/d) to leptin (125microg/kg/d), and to the combination of amylin (50microg/kg/d) and leptin (125microg/kg/d), was also explored in DIO rats via sustained subcutaneous infusion for 14days. Infusion of amylin/leptin/CCK for 14days exerted significantly greater body weight loss, inhibition of food intake, and reduction in adiposity compared to amylin/leptin treatment alone in DIO rats. However, co-infusion of CCK and leptin was an ineffective weight loss regimen in this model. Whereas CCK agonism alone is ineffective at eliciting or maintaining weight loss, it durably augmented the food intake and body weight-lowering effects of amylin and amylin/leptin in a relevant disease model, and when combined with amylin, cooperatively activated neurons within the caudal brainstem.

Topics: Amyloid; Analysis of Variance; Animals; Appetite Depressants; Area Postrema; Body Weight; Cholecystokinin; Disease Models, Animal; Dopamine beta-Hydroxylase; Dose-Response Relationship, Drug; Drug Therapy, Combination; Eating; Islet Amyloid Polypeptide; Leptin; Male; Neurons; Obesity; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Weight Loss

Mitogen-activated protein (MAP) kinases and nuclear factor kappa B (NF-kappaB) are implicated in early stages of acute pancreatitis pathogenesis. We investigated the relationship between the p38 MAP kinase and NF-kappaB in isolated acinar cells.. Isolated rodent acinar cells were stimulated with agonists after infection with an adenovector containing a luciferase promoter driven only by NF-kappaB and an adenovector containing the dominant negative (DN) form of p38 (empty vector in controls).. Initial immunoblots confirmed that the agonist stimulated p38 activation in acinar cells was substantially attenuated by DN p38 overexpression. Stimulation of native cholecystokinin (CCK)-A receptors or tumor necrosis factor-alpha (TNF-alpha) receptors promoted a significant increase in NF-kappaB-dependent gene transcription in cells infected with the empty vector, while overexpression of DN p38 significantly abrogated NF-kappaB-dependent luciferase activity.. These findings support our hypothesis that p38 is involved in the activation of proinflammatory nuclear transcription factors such as NF-kappaB in pancreatic exocrine cells.

Topics: Animals; Cells, Cultured; Cholecystokinin; Disease Models, Animal; Gene Expression; Mice; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Pancreas, Exocrine; Rats; Transcription, Genetic; Tumor Necrosis Factor-alpha

Perisomatic inhibition from basket cells plays an important role in regulating pyramidal cell output. Two major subclasses of CA1 basket cells can be identified based on their expression of either cholecystokinin (CCK) or parvalbumin. This study examined their fates in the mouse pilocarpine model of temporal lobe epilepsy. Overall, immunohistochemical labeling of GABAergic boutons in the pyramidal cell layer of CA1 was preserved in the mouse model. However, CCK-labeled boutons in this layer were chronically reduced, whereas parvalbumin-containing boutons were conserved. Immunohistochemistry for cannabinoid receptor 1 (CB(1)), another marker for CCK-containing basket cells, also labeled fewer boutons in pilocarpine-treated mice. Hours after status epilepticus, electron microscopy revealed dark degenerating terminals in the pyramidal cell layer with lingering CCK and CB(1) immunoreactivity. In mice with recurrent seizures, carbachol-induced enhancement of spontaneous IPSCs (sIPSCs) originating from CCK-containing basket cells was accordingly reduced in CA1 pyramidal cells. By suppressing sIPSCs from CCK-expressing basket cells, a CB(1) agonist reverted the stimulatory effects of carbachol in naive mice to levels comparable with those observed in cells from epileptic mice. The agatoxin-sensitive component of CA1 pyramidal cell sIPSCs from parvalbumin-containing interneurons was increased in pilocarpine-treated mice, and miniature IPSCs were reduced, paralleling the decrease in CCK-labeled terminals. Altogether, the findings are consistent with selective reduction in perisomatic CA1 pyramidal cell innervation from CCK-expressing basket cells in mice with spontaneous seizures and a greater reliance on persisting parvalbumin innervation. This differential alteration in inhibition may contribute to the vulnerability of the network to seizure activity.

Topics: Animals; CA1 Region, Hippocampal; Cholecystokinin; Disease Models, Animal; Epilepsy, Temporal Lobe; gamma-Aminobutyric Acid; Inhibitory Postsynaptic Potentials; Male; Mice; Neural Pathways; Neurons; Parvalbumins; Pilocarpine; Presynaptic Terminals; Pyramidal Cells; Receptor, Cannabinoid, CB1; Status Epilepticus

Secretory granules are acidic; cell secretion will therefore lead to extracellular acidification. We propose that during secretion, protons co-released with proteins from secretory granules of pancreatic acinar cells acidify the restricted extracellular space of the pancreatic lumen to regulate normal physiological and pathophysiological functions in this organ. Extracellular changes in pH were quantified in real time using 2-photon microscopy analysis of pancreatic tissue fragments from mouse models of acute pancreatitis (mice given physiological concentrations [10 -20 pM] of cholecystokinin or high concentrations of [100 nM] cerulein). The effects of extracellular changes in pH on cell behavior and structures were measured.. With physiological stimulation, secretory granule fusion (exocytosis) caused acidification of the pancreatic lumen. Acidifications specifically affected intracellular calcium responses and accelerated the rate of recovery from agonist-evoked calcium signals. Protons therefore appear to function as negative-feedback, extracellular messengers during coupling of cell stimuli with secretion. At high concentrations of cerulein, large increases in secretory activity were associated with extreme, prolonged acidification of the luminal space. These pathological changes in pH led to disruption of intercellular junctional coupling, measured by movement of occludin and E-cadherin.. By measuring changes in extracellular pH in pancreas of mice, we observed that luminal acidification resulted from exocytosis of zymogen granules from acinar cells. This process is part of normal organ function but could contribute to the tissue damage in cases of acute pancreatitis.

Topics: Animals; Ceruletide; Cholagogues and Choleretics; Cholecystokinin; Disease Models, Animal; Endocytosis; Exocytosis; Extracellular Fluid; Hydrogen-Ion Concentration; Mice; Pancreas; Pancreatitis, Acute Necrotizing; Secretory Vesicles

To investigate chronic stress as a susceptibility factor for developing pancreatitis, as well as tumor necrosis factor-α (TNF-α) as a putative sensitizer.. Rat pancreatic acini were used to analyze the influence of TNF-α on submaximal (50 pmol/L) cholecystokinin (CCK) stimulation. Chronic restraint (4 h every day for 21 d) was used to evaluate the effects of submaximal (0.2 μg/kg per hour) cerulein stimulation on chronically stressed rats.. In vitro exposure of pancreatic acini to TNF-α disorganized the actin cytoskeleton. This was further increased by TNF-α/CCK treatment, which additionally reduced amylase secretion, and increased trypsin and nuclear factor-κB activities in a protein-kinase-C δ and ε-dependent manner. TNF-α/CCK also enhanced caspases' activity and lactate dehydrogenase release, induced ATP loss, and augmented the ADP/ATP ratio. In vivo, rats under chronic restraint exhibited elevated serum and pancreatic TNF-α levels. Serum, pancreatic, and lung inflammatory parameters, as well as caspases'activity in pancreatic and lung tissue, were substantially enhanced in stressed/cerulein-treated rats, which also experienced tissues' ATP loss and greater ADP/ATP ratios. Histological examination revealed that stressed/cerulein-treated animals developed abundant pancreatic and lung edema, hemorrhage and leukocyte infiltrate, and pancreatic necrosis. Pancreatitis severity was greatly decreased by treating animals with an anti-TNF-α-antibody, which diminished all inflammatory parameters, histopathological scores, and apoptotic/necrotic markers in stressed/cerulein-treated rats.. In rats, chronic stress increases susceptibility for developing pancreatitis, which involves TNF-α sensitization of pancreatic acinar cells to undergo injury by physiological cerulein stimulation.

Topics: Actins; Adenosine Diphosphate; Adenosine Triphosphate; Amylases; Animals; Antibodies; Calcium Signaling; Caspases; Ceruletide; Cholecystokinin; Chronic Disease; Cytoskeleton; Disease Models, Animal; Enzyme Activation; Lung Injury; Male; Necrosis; NF-kappa B; Pancreas, Exocrine; Pancreatitis; Protein Kinase C-delta; Protein Kinase C-epsilon; Protein Transport; Rats; Rats, Wistar; Restraint, Physical; Severity of Illness Index; Stress, Psychological; Tissue Culture Techniques; Trypsin; Tumor Necrosis Factor-alpha

Glucocorticoids have major effects on food intake, demonstrated by the decrease of food intake following adrenalectomy. Satiety signals are relayed to the nucleus of the solitary tract (NTS), which has reciprocal projections with the arcuate nucleus (ARC) and paraventricular nucleus (PVN) of the hypothalamus. We evaluated the effects of glucocorticoids on the activation of hypothalamic and NTS neurons induced by food intake in rats subjected to adrenalectomy (ADX) or sham surgery 7 days before the experiments. One-half of ADX animals received corticosterone (ADX+B) in the drinking water (B: 25 mg/l). Fos/tyrosine hydroxylase (TH), Fos/corticotrophin-releasing factor (CRF) and Fos immunoreactivity were assessed in the NTS, PVN, and ARC, respectively. Food intake and body weight were reduced in the ADX group compared with sham and ADX+B groups. Fos and Fos/TH in the NTS, Fos, and Fos/CRF immunoreactive neurons in the PVN and Fos in the ARC were increased after refeeding, with higher number in the ADX group, compared with sham and ADX+B groups. CCK administration showed no hypophagic effect on ADX group despite a similar increase of Fos/TH immunoreactive neurons in the NTS compared with sham and ADX+B groups, suggesting that CCK alone cannot further increase the anorexigenic effect induced by glucocorticoid deficiency. The present data indicate that glucocorticoid withdrawal reduced food intake, which was associated with higher activation of ARC, CRF neurons of the PVN, and catecholaminergic neurons of the NTS. In the absence of glucocorticoids, satiety signals elicited during a meal lead to an augmented activation of brain stem and hypothalamic pathways.

Topics: Adrenalectomy; Animals; Arcuate Nucleus of Hypothalamus; Behavior, Animal; Body Weight; Catecholamines; Cholecystokinin; Corticosterone; Corticotropin-Releasing Hormone; Disease Models, Animal; Drinking; Eating; Fasting; Feeding and Eating Disorders; Glucocorticoids; Hypothalamus; Male; Neural Pathways; Neurons; Paraventricular Hypothalamic Nucleus; Proto-Oncogene Proteins c-fos; Rats; Rats, Wistar; Satiety Response; Solitary Nucleus; Tyrosine 3-Monooxygenase

Monosodium glutamate (MSG) treatment of neonatal mice results in a selective damage to the arcuate nucleus (ARC) and development of obesity with increased adiposity at sustained body weight in the adulthood. Feeding pattern of the MSG obese mice is unusual. Our previous results showed that after 24-h fasting, MSG mice consumed negligible amount of food in several hours and therefore, it was impossible to register the effect of peptides attenuating food intake such as cholecystokinin (CCK) or cocaine- and amphetamine-regulated transcript (CART) peptide. To overcome this problem, two findings were used: firstly, orexigenic effect of neuropeptide Y (NPY) was attenuated both by CCK or CART peptide in lean fed mice and secondly, orexigenic effect of NPY was preserved in fed rats with MSG obesity. In this study, short-term food intake in fed lean and MSG obese C57BL/6 male mice was measured after simultaneous central administration of orexigenic NPY with either CART peptide or peripherally administered CCK. Anorexigenic action of exogenous CART peptide was preserved in MSG obese mice. On the other hand, satiety effect of exogenous CCK was completely lost in MSG obese mice. In conclusion, effective leptin signaling in ARC is necessary for satiety effect of CCK.

Topics: Animals; Appetite Regulation; Arcuate Nucleus of Hypothalamus; Cholecystokinin; Disease Models, Animal; Male; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins; Neuropeptide Y; Obesity; Sodium Glutamate

Animal models of inflammatory pain are characterized by the release of inflammatory mediators such as cytokines and neurotrophic factors, and enhanced analgesic sensitivity to opioids. In this study, we examine the mechanisms underlying this effect, in particular the roles of cholecystokinin (CCK) and nerve growth factor (NGF), in an animal model of central nervous system (CNS) inflammation induced by spinal administration of lipopolysaccharide (LPS). Although spinal administration of LY-225910 (25 ng), a CCK-B antagonist, enhanced morphine analgesia in naïve rats, it was unable to do so in LPS-treated animals. Conversely, spinal CCK-8S administration (1 ng) decreased morphine analgesia in LPS-treated rats, but not in naïve animals. Further, spinal anti-NGF (3 microg) was able to reduce morphine analgesia in LPS-treated rats, but not in naïve animals, an effect that was reversed by spinal administration of LY-225910. While CCK-8S concentration was increased in spinal cord extracts of LPS animals as compared to controls, morphine-induced spinal CCK release in the extracellular space, as measured by in-vivo spinal cord microdialysis was inhibited in LPS animals as compared to controls, and this was reversed by anti-NGF pretreatment. Finally, chronic spinal administration of beta-NGF (7 microg/day) for 7 days enhanced spinal morphine analgesia, possibly by mimicking a CNS inflammatory state. We suggest that in intrathecally LPS-treated rats, spinal CCK release is altered resulting in enhanced morphine analgesia, and that this mechanism may be regulated to an important extent by NGF.

Topics: Analgesics; Animals; Central Nervous System Diseases; Cholecystokinin; Disease Models, Animal; Inflammation; Injections, Spinal; Lipopolysaccharides; Male; Morphine; Nerve Growth Factor; Rats; Rats, Long-Evans; Sincalide; Spinal Cord

The principal causative pathology of Parkinson disease is the progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta projecting to the striatum in the brain. The information regarding the expression of neuropeptides in parkinsonism is very limited. Here we have elucidated striatal neuropeptide mechanisms in experimental parkinsonism using the unilateral 6-hydroxydopamine model to degenerate dopamine neurons. A thoroughly controlled sample preparation technique together with a peptidomics approach and targeted neuropeptide sequence collections enabled sensitive detection, identification, and relative quantitation of a great number of endogenous neuropeptides. Previously not recognized alterations in neuropeptide levels were identified in the unilateral lesioned mice with or without subchronic 3,4-dihydroxy-L-phenylalanine administration, the conventional treatment of Parkinson disease. Several of these peptides originated from the same precursor such as secretogranin-1, somatostatin, prodynorphin, and cholecystokinin. Disease-related biotransformation of precursors into individual peptides was observed in the experimental model of Parkinson disease. Several previously unreported potentially biologically active peptides were also identified from the striatal samples. This study provides further evidence that neuropeptides take part in mediating the central nervous system failure associated with Parkinson disease.

Topics: Amino Acid Sequence; Animals; Cholecystokinin; Chromogranin B; Disease Models, Animal; Enkephalins; Mice; Molecular Sequence Data; Neostriatum; Oxidopamine; Parkinson Disease; Peptides; Postmortem Changes; Protein Precursors; Reproducibility of Results; Somatostatin; Tissue Extracts; Tyrosine 3-Monooxygenase

The effects on gastric emptying of feeding with a normal diet (ND), an early high-calorie and hyperosmolar diet (HCHOD) or normal diet plus intraperitoneal loxiglumide (LOX) were investigated in rats with antecolic (ACGJ) or retrocolic (RCGJ) gastrojejunostomy.. Sixty rats were separated into six groups of ten animals each (ACGJ+ND, RCGJ+ND, ACGJ+HCHOD, RCGJ+HCHOD, ACGJ+ND+LOX, and RCGJ+ND+LOX). On the seventh day, scintigraphic measurements of solid gastric emptying were made at 1, 30 and 60 min.. According to the 60-min results, the RCGJ+ND group exhibited delayed emptying compared to the ACGJ+ND group (p=0.023). Gastric emptying of ACGJ+HCHOD rats was delayed compared with the other ACGJ groups (compared to ACGJ+ND: p=0.000, and ACGJ+ND+LOX: p=0.015). Gastric emptying was more effective in the RCGJ+ND+LOX group than the other RCGJ groups (compared to RCGJ+ND: p=0.003, and RCGJ+HCHOD: p=0.001).. Antecolic gastrojejunostomy provided better gastric emptying. An early high-calorie and hyperosmolar enteral diet delayed gastric emptying in both types of anastomosis.

Topics: Anastomosis, Surgical; Animals; Cholecystokinin; Disease Models, Animal; Enteral Nutrition; Female; Gastric Bypass; Gastric Emptying; Hormone Antagonists; Jejunum; Male; Proglumide; Rats; Rats, Wistar; Stomach

Leptin is thought to reduce food intake, in part, by increasing sensitivity to satiation signals, including CCK. Leptin action in both forebrain and hindbrain reduces food intake, and forebrain leptin action augments both the anorexic and neuronal activation responses to CCK. Here, we asked whether leptin signaling in hindbrain also enhances these responses to CCK. We found that food intake was strongly inhibited at 30 min after a combination of 4th-intracerebroventricular (4th-icv) leptin injection and intraperitoneal CCK administration, whereas neither hormone affected intake during this period when given alone. Leptin injections targeted directly at the dorsal vagal complex (DVC) similarly enhanced the anorexic response to intraperitoneal CCK. Intra-DVC leptin injection also robustly increased the number of neurons positive for phospho-STAT3 staining in the area surrounding the site of injection, confirming local leptin receptor activation. Conversely, the anorexic response to 4th-icv leptin was completely blocked by IP devazepide, a CCKA-R antagonist, suggesting that hindbrain leptin reduces intake via a mechanism requiring endogenous CCK signaling. We then asked whether hindbrain leptin treatment enhances the dorsomedial hindbrain, hypothalamus, or amygdala c-Fos responses to IP CCK. We found that, in contrast to the effects of forebrain leptin administration, 4th-icv leptin injection had no effect on CCK-induced c-Fos in any structures examined. We conclude that leptin signaling in either forebrain or hindbrain areas can enhance the response to satiation signals and that multiple distinct neural circuits likely contribute to this interaction.

Topics: Animals; Anorexia; Cholecystokinin; Devazepide; Disease Models, Animal; Eating; Hormone Antagonists; Injections, Intraventricular; Leptin; Male; Proto-Oncogene Proteins c-fos; Rats; Rats, Wistar; Receptors, Leptin; Rhombencephalon; Satiety Response; STAT3 Transcription Factor; Vagus Nerve

Genetic invalidation of CCK(2) receptors abolishes chronic constriction injury (CCI) induced mechanical hypersensitivity in mice. However, housing in environmentally enriched conditions significantly alters the phenotype of CCK(2) receptor deficient mice in all major behavioral domains. Furthermore, environmental enrichment itself has been reported to have protective effects in several rodent models of neurological diseases (brain and spinal trauma, ischemic stroke, Alzheimer's disease, etc.). In the present study we reproduced the earlier finding that mice, lacking CCK(2) receptors (-/-) are resistant to CCI-induced hypersensitivity. On the other hand, environmental enrichment substantially reduced CCI-induced mechanical hypersensitivity in wild-type (+/+) mice. Nevertheless, the phenotypic differences between wild-type (+/+) and mutant (-/-) mice in mechanical sensitivity before and after CCI-surgery were not eliminated by alternative housing conditions. These observations suggest that environmental enrichment has beneficial effects in neuropathic conditions and reinforce the causal link between CCK(2) receptors, mechanical sensitivity and the development of CCI-induced hypersensitivity.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Down-Regulation; Environment, Controlled; Female; Genetic Predisposition to Disease; Housing, Animal; Hyperalgesia; Ligation; Male; Mechanoreceptors; Mice; Mice, Inbred C57BL; Mice, Knockout; Peripheral Nerve Injuries; Peripheral Nerves; Peripheral Nervous System Diseases; Phenotype; Photic Stimulation; Receptor, Cholecystokinin B

Pancreatitis is a disease with high morbidity and mortality. In vitro experiments on pancreatic acini showed that supramaximal but not submaximal cholecystokinin (CCK) stimulation induces effects in the acinar cell that can be correlated with acinar morphological changes observed in the in vivo experimental model of cerulein-induced pancreatitis. The GTPase Rac1 was previously reported to be involved in CCK-evoked amylase release from pancreatic acinar cells. Here, we demonstrate that pretreatment with the Rac1 inhibitor NSC23766 (100 microM, 2 h) effectively blocked Rac1 translocation and activation in CCK-stimulated pancreatic acini, without affecting activation of its closely related GTPase, RhoA. This specific Rac1 inhibition decreased supramaximal (10 nM) CCK-stimulated acinar amylase release (27.% reduction), which seems to be connected to the reduction observed in serum amylase (46.6% reduction) and lipase levels (46.1% reduction) from cerulein-treated mice receiving NSC23766 (100 nmol h(-1)). The lack of Rac1 activation also reduced formation of reactive oxygen species (ROS; 20.8% reduction) and lactate dehydrogenase release (LDH; 24.3% reduction), but did not alter calcium signaling or trypsinogen activation in 10 nM CCK-stimulated acini. In the in vivo model, the cerulein-treated mice receiving NSC23766 also presented a decrease in both pancreatic and lung histopathological scores (reduction in oedema, 32.4 and 66.4%; haemorrhage, 48.3 and 60.2%; and leukocyte infiltrate, 53.5 and 43.6%, respectively; reduction in pancreatic necrosis, 65.6%) and inflammatory parameters [reduction in myeloperoxidase, 52.2 and 38.9%; nuclear factor kappaB (p65), 61.3 and 48.6%; and nuclear factor kappaB (p50), 46.9 and 44.9%, respectively], together with lower serum levels for inflammatory (TNF-alpha, 40.4% reduction) and cellular damage metabolites (LDH, 52.7% reduction). Collectively, these results suggest that pharmacological Rac1 inhibition ameliorates the severity of pancreatitis and pancreatitis-associated lung injury through the reduction of pancreatic acinar damage induced by pathological digestive enzyme secretion and overproduction of ROS.

Topics: Aminoquinolines; Amylases; Animals; Calcium; Cell Membrane; Ceruletide; Cholagogues and Choleretics; Cholecystokinin; Cytosol; Disease Models, Animal; Dose-Response Relationship, Drug; Lung Diseases; Male; Mice; Mice, Inbred C57BL; Neuropeptides; Pancreatitis; Pyrimidines; rac GTP-Binding Proteins; rac1 GTP-Binding Protein; Reactive Oxygen Species; Severity of Illness Index

To demonstrate the relationship between prolonged alcohol intake and chronic pancreatitis.. Wistar rats were fed diet containing 25% concentration (vol/vol) of ethanol for 6 months. Cholecystokinin (CCK) was quantified by radioimmunoassay. Immunohistochemistry was used to detect alpha-smooth muscle actin, cyclooxygenase 2, and toll-like receptor 4 in rat pancreas. Western-blot was used to quantitatively determine the expression of nuclear factor kappaB and the above inflammatory markers. Pancreatic collagen content was quantified by measuring OH-proline. Superoxide dismutase was measured by colorimetric method.. In contrast to the control group, there was little histological change in pancreatic tissue but obvious ultrastructural changes in acinar cells of the ethanol group. Cholecystokinin, amylase, and lipase were found reduced in the ethanol group. Chronic ethanol intake did not elicit any change in the expression of alpha-smooth muscle actin, cyclooxygenase 2, toll-like receptor 4, nuclear factor kappaB, pancreatic collagen, and superoxide dismutase.. Long-term alcohol consumption did not cause chronic pancreatitis but impaired exocrine pancreatic function. The mechanism behind it could be associated with decreased output of intestinal CCK and lower concentration of pancreatic CCK. Furthermore, the nonoxidative pathway of ethanol metabolism was probably involved in it.

Topics: Alcoholism; Amylases; Animals; Cholecystokinin; Disease Models, Animal; Inflammation Mediators; Intestine, Small; Lipase; Male; NF-kappa B; Pancreas; Pancreatitis, Alcoholic; Rats; Rats, Wistar; Signal Transduction; Toll-Like Receptor 4

Cholecystokinin (CCK) involvement in depression-like disorders is poorly documented. Here, we investigated whether CCKergic neurotransmission is relevant to depressive-like symptoms and antidepressant therapy using a novel preclinical model based on repeated social defeat over 4 weeks in rats. Repeated social defeat triggers changes that could be considered as behavioral and biological correlates of depressive symptoms in humans, such as a hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis (increase of serum corticosterone levels and of adrenal gland weight), increased immobility time in the forced swimming test (FST), decrease of body weight and of sweet water consumption and reduction of hippocampal volume associated with a decreased cell proliferation in the dentate gyrus. In addition, in vivo microdialysis showed that cortical CCK release was tonically increased in defeated rats. Chronic imipramine treatment (16 mg kg(-1) per day for 25 days) prevented both the repeated social defeat-induced alterations of biological and behavioral parameters and the associated increase of cortical CCK release. Chronic blockade of CCK2 receptors by the specific antagonist CI-988 (1 mg kg(-1) per day for 25 days) also normalized immobility time in the FST and prevented HPA axis hyperactivity, reduction of hippocampal volume and cell proliferation and decreased sweet water intake normally evoked by repeated social defeat. These data showed that the repeated social-defeat paradigm can be considered as a suitable model of 'depression' in rats. The causal link between social defeat-evoked (1) increase in cortical CCKergic neurotransmission and (2) depression-like symptoms that we highlighted here strongly suggests that CCKergic systems may be a relevant target for novel antidepressant therapy.

Topics: Analysis of Variance; Animals; Antidepressive Agents, Tricyclic; Bromodeoxyuridine; Cell Proliferation; Cholecystokinin; Corticosterone; Depression; Disease Models, Animal; Dominance-Subordination; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Hippocampus; Imipramine; Male; Microdialysis; Phosphopyruvate Hydratase; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Social Environment; Swimming

Cholecystokinin (CCK) stimulates the release of amylase and lipase from the normal pancreas. However, it is not clear to what extent this occurs in the early stages of pancreatitis induced by biliary tract obstruction in the rat and whether CCK initiates an inflammatory cascade in this condition.. Selective CCK1 receptor antagonists, JNJ-17156516 ((S)-(3-[5-(3,4-dichloro-phenyl)-1-(4-methoxy-phenyl)-1H-pyrazol-3-yl]-2-m-tolyl-propionic acid) and dexloxiglumide, were used to assess the response of plasma amylase and lipase to a CCK analogue, CCK8S, in normal rats and in rats with bile duct ligation.. Both antagonists suppressed CCK8S-induced elevation of plasma amylase activity in normal rats. JNJ-17156516 was more potent than dexloxiglumide (ED(50)=8.2 vs >30 micromol kg(-1) p.o.) and produced a longer lived inhibition (6 vs 2 h). Plasma amylase and lipase activity were elevated in parallel to CCK plasma concentrations after bile duct ligation and both activities were suppressed in a dose-dependent manner by JNJ-17156516 and dexloxiglumide. JNJ-17156516 was approximately 5- to 10-fold more potent than dexloxiglumide. Infusion of CCK8S to naïve rats to achieve levels similar to those observed after bile duct ligation (20 pM) increased plasma amylase activity and activated nuclear factor-kappaB in the pancreas. These effects were prevented by pretreatment with JNJ-17156516.. The elevation of plasma amylase and lipase activity in the early stages of obstruction-induced pancreatitis is largely driven by elevation of plasma CCK concentration and activation of CCK1 receptors. These data show that CCK is an initiating factor in acute pancreatitis in the rat.

Topics: Acute Disease; Amylases; Animals; Bile Ducts; Cholecystokinin; Disease Models, Animal; Ligation; Lipase; Male; NF-kappa B; Pancreatitis; Pentanoic Acids; Phenylpropionates; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Sincalide

Several animal models have been developed to investigate the pathobiology of pancreatitis, but few studies have examined the effects that altered pancreatic gene expression have in these models. In this study, the sensitivity to secretagogue-induced pancreatitis was examined in a mouse line that has an altered acinar cell environment due to the targeted deletion of Mist1. Mist1 is an exocrine specific transcription factor important for the complete differentiation and function of pancreatic acinar cells. Mice lacking the Mist1 gene [Mist1 knockout (KO) mice] exhibit cellular disorganization and functional defects in the exocrine pancreas but no gross morphological defects. Following the induction of pancreatitis with caerulein, a CCK analog, we observed elevated serum amylase levels, necrosis, and tissue damage in Mist1 KO mice, indicating increased pancreatic damage. There was also a delay in the regeneration of acinar tissue in Mist1 KO animals. Molecular profiling revealed an altered activation of stress response genes in Mist1 KO pancreatic tissue compared with wild-type (WT) tissue following the induction of pancreatitis. In particular, Western blot analysis for activating transcription factor 3 and phosphorylated eukaryotic initiation factor 2alpha (eIF2alpha), mediators of endoplasmic reticulum (ER) stress, indicated limited activation of this pathway in Mist1 KO animals compared with WT controls. Conversely, Mist1 KO pancreatic tissue exhibits increased expression of growth arrest and DNA damage inducible 34 protein, an inhibitor of eIF2alpha phosphorylation, before and after the induction of pancreatitis. These finding suggest that activation of the ER stress pathway is a protective event in the progression of pancreatitis and highlight the Mist1 KO mouse line as an important new model for studying the molecular events that contribute to the sensitivity to pancreatic injury.

Topics: Activating Transcription Factor 3; Acute Disease; Amylases; Animals; Antigens, Differentiation; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Cell Cycle Proteins; Cells, Cultured; Ceruletide; Cholecystokinin; Disease Models, Animal; Dose-Response Relationship, Drug; Endoplasmic Reticulum; Eukaryotic Initiation Factor-2; Gene Expression; Immediate-Early Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Pancreas, Exocrine; Pancreatitis; Protein Phosphatase 1; Regeneration; RNA, Messenger; Severity of Illness Index; Stress, Physiological; Time Factors

Structures within the piriform cortex (PC) including the endopiriform nucleus (DEN) and pre-endopiriform nucleus (pEn) have been implicated to be involved in seizure genesis in models of temporal lobe epilepsy. We used stereological methods to examine the specificity and extent of neuron loss in the PC of pilocarpine-treated rats. Both 7 days and 2 months post-status epilepticus rats showed significant neuron loss in the pEn and DEN, layer III of the intermediate PC, and layers II and III of the caudal PC. Total losses in the PC were 40 and 46% in 7 days and 2 months post-status epilepticus rats, respectively (p<0.01). The numbers of parvalbumin (PV)- and cholecystokinin (CCK)-immunopositive neuron profiles significantly decreased, and somatostatin (SS)-immunopositive neuron profiles tended to decrease. A large decrease in the number of PV-immunopositive neuron profiles occurred in the pEn, adjoining parts of the DEN and deep layer III of the PC, portions of the DEN bordering the claustrum and agranular insular cortex, and layer III of the caudal PC. The regions with decreased numbers of PV-, CCK-, and SS-immunopositive neuron profiles overlapped with those where many Nissl-stained neurons were lost and many degenerating cell bodies were detected. These results suggest that the decreases in the numbers of PV/SS/CCK-immunopositive neurons are related to neuron loss rather than to a low rate of synthesis of their peptides or proteins.

Topics: Animals; Cell Death; Cerebral Cortex; Cholecystokinin; Disease Models, Animal; Immunohistochemistry; Male; Neurons; Nissl Bodies; Parvalbumins; Pilocarpine; Rats; Rats, Sprague-Dawley; Seizures; Somatostatin; Status Epilepticus

The main purpose of this study was to evaluate the effects of early dexamethasone treatment on pain-related peptides at an early stage in the development of neuropathic pain induced by implantation of a sciatic nerve cuff in Sprague Dawley rats (body weight 250 to 350 g). The rats were tested for touch sensitivity with the use of von Frey filaments before and 3 d after cuff implantation (n = 12) or sham surgery (n = 6). Half of the cuff-implanted rats received dexamethasone, 1 mg/kg intraperitoneally, 1 h after surgery. Spinal cords were collected on the 3rd day after surgery, and the lumbar enlargement was processed for the detection of selected peptides (neurotensin, substance P, cholecystokinin [CCK], vasoactive intestinal peptide, and calcitonin gene-related peptide) by means of liquid chromatography and tandem mass spectrometry. The right sciatic nerve of each rat was collected, fixed, and stained for histopathological evaluation. Except for neurotensin, all the peptides showed an increased concentration with neuropathic pain; however, the differences were significant (P < 0.05) only for substance P and CCK. In the animals treated with dexamethasone, mechanical allodynia was less pronounced (P < 0.01), and only the concentration of substance P was decreased significantly (P < 0.05). Sciatic nerve sections showed a decrease in C (P < 0.01) and Adelta (P < 0.03) fibres with neuropathic pain and a nearly normal percentage of C fibres after dexamethasone treatment. The dexamethasone-treated animals also had less inflammation detectable microscopically at the nerve constriction site compared with cuff-implanted animals that were not treated with dexamethasone. Our results suggest that in the early stages of neuropathic pain induced by an inflammatory process, dexamethasone may be a useful treatment and that substance P plays an important role in pain perception.

Topics: Animals; Anti-Inflammatory Agents; Calcitonin; Cholecystokinin; Chromatography, Liquid; Constriction; Dexamethasone; Disease Models, Animal; Male; Mass Spectrometry; Nerve Fibers; Neurotensin; Random Allocation; Rats; Rats, Sprague-Dawley; Sciatic Nerve; Sciatic Neuropathy; Spinal Cord; Substance P; Time Factors; Treatment Outcome

Brain cholecystokinin (CCK) and its receptor CCK(2) have been implicated in the etiology of anxiety. CCK(2) antagonists, however, fail to ameliorate anxiety in humans. In this study, a role for CCK in adaptation to stress is investigated by testing carry-over effects of Ly225.910, a potent CCK(2) antagonist, in a rat model of individual differences in novelty-induced emotionality. Novelty-seeking behavior in the rat is thought to model some aspects of sensation-seeking, a personality trait closely associated with risk activities including substance abuse. Animals were categorized as high-responders (HR) and low-responders (LR) based on the activity response to an inescapable novel environment. High-responders exhibit increased exploration and proactive behavior while low-responders are less exploratory and deemed to behave more anxiously. We analyzed the effects of the CCK(2) antagonist Ly225.910 (0.1 mg/kg or 0.5 mg/kg, i.p.) on the anxiety displayed by HR and LR rats in the light-dark (LD) box test (Day 1). Treatment and phenotype effects were not acutely evident. LD-experienced rats were then re-exposed to drug-free LD-box (Days 4 and 11) and elevated plus-maze (EPM) test (Day 14). Drug-naïve HR rats behaved less anxiously than drug-naïve LR rats while exploring the open arms. Previous exposure to the antagonist curtailed these differences. The emotional responses in drug-naïve HR and LR rats to the EPM test could reflect different degrees of adaptation to anxiety-like training. Long-term effects of Ly225.910 on EPM-induced risk assessment in HR and LR rats suggest that CCK-system may be involved in modulating preparedness to arousing environmental changes.

Topics: Adaptation, Physiological; Animals; Behavior, Animal; Cholecystokinin; Disease Models, Animal; Dose-Response Relationship, Drug; Exploratory Behavior; Male; Maze Learning; Quinazolinones; Rats; Rats, Sprague-Dawley; Reaction Time; Receptors, Cholecystokinin; Stress, Psychological

Black Tea Extract (BTE), a phytocompound has been attributed with a plethora of health-promoting actions. We have previously demonstrated that BTE inhibits chronic hepatitis in a rat model induced with high-fat and ethanol (EtOH). This study reports that BTE prevents altered pancreatic acinar cell functions, oxidative stress, inflammatory changes and DNA damage in the EtOH+cholecystokinin (CCK)-induced model of pancreatitis. The EtOH+CCK model rats were administered with BTE, and were examined the activity of pancreatic digestive enzymes (amylase and lipase), proinflammatory cytokines (IL-6 and TNF-alpha), oxidative and antioxidative enzymes (nitric oxide, NO; malondialdehyde, MDA; superoxide dismutase, SOD; catalase, CAT), antioxidant level (glutathione, GSH), histopathological changes and the integrity of genomic DNA. Results show that because of chronic EtOH treatment, serum level of amylase and lipase (two biomarkers for pancreatitis) and pancreatic levels of MDA and NO (two biomarkers of oxidative stress) increased significantly, which could be effectively blunted by BTE. BTE could normalize EtOH+CCK-induced suppressed activities of SOD and CAT, and GSH content of pancreatic tissue. Also, histopathological and inflammatory changes during EtOH+CCK-induced pancreatitis could be blunted by BTE. Furthermore, BTE could effectively reduce EtOH+CCK-induced increase in DNA fragmentation and damage. These findings suggest that BTE prevents pancreatitis caused by chronic EtOH+CCK toxicity presumably by enhancing antioxidant, anti-inflammatory and antiapoptotic activity in rats.

Topics: Amylases; Animals; Antioxidants; Camellia sinensis; Cholecystokinin; Chronic Disease; Cytokines; Disease Models, Animal; Ethanol; Glutathione; Lipase; Lipid Peroxidation; Male; Pancreas; Pancreatitis; Plant Leaves; Rats; Tea

Gastrointestinal inflammation reduces food intake but the biological mechanisms explaining suppressed feeding during inflammation are unknown. We have used a model of upper gut infection (Trichinella spiralis in the mouse) to study the effect of inflammation on food intake, and explored the role of a key enteroendocrine cell (EEC) in the regulation of feeding by the immune response.. Food intake of NIH mice infected with the intestinal nematode Trichinella spiralis was measured. Duodenal cholecystokinin (CCK) cells were counted. Plasma CCK was measured. Infected mice were treated with a specific CCK1 receptor antagonist, and food intake reassessed. The influence of the immune response on food intake and CCK was mechanistically examined by treating mice with CD4 or mast cell neutralising antibodies. The role of the T helper 2 response was further explored in mice genetically deficient for interleukin (IL)-4, IL-13, or IL-4Ralpha (receptor alpha subunit).. Food intake of infected mice was significantly reduced at the temporal peak of intestinal inflammation. CCK expressing EEC were upregulated in infected mice, and plasma CCK levels were increased. A CCK1 receptor antagonist restored the food intake of infected mice to a significant degree. Furthermore, suppression of food intake was completely abolished in the absence of CD4+ T lymphocytes or IL-4Ralpha.. The data show for the first time that intestinal inflammation results in reduced food intake due to upregulation of CCK. Moreover, following infection, food intake and CCK expressing cells are under the specific control of CD4+ T-cells, via release of IL-4 and IL-13.

Topics: Animals; Cell Count; Cholecystokinin; Cytokines; Disease Models, Animal; Duodenum; Eating; Enteroendocrine Cells; Feeding and Eating Disorders; Immunohistochemistry; Interleukins; Intestine, Small; Mast Cells; Mice; Mice, Inbred BALB C; Mice, Inbred Strains; Receptors, Cholecystokinin; Th2 Cells; Trichinella spiralis; Trichinellosis

Topics: Acute Disease; Animals; Calcium; Cholecystokinin; Cytosol; Devazepide; Disease Models, Animal; Pancreas; Pancreatitis

Pancreatic duct obstruction induces edematous but not hemorrhagic pancreatitis even when combined with maximal secretory stimulation. The aim of the present study was to test the hypothesis that pancreatic and bile duct obstruction exacerbates edematous pancreatitis induced by supramaximal secretory stimulation by caerulein.. In in vivo studies using rats, biliopancreatic duct ligation was combined with supramaximal stimulation of caerulein, and pancreatic histology, serum amylase level, pancreatic edema, and intrapancreatic trypsin activation were evaluated. In in vitro studies, the pancreatic acini were isolated from the rats with biliopancreatic duct ligation, and amylase secretion, intracellular trypsin activation, and acinar cell fragility were evaluated.. Biliopancreatic duct ligation exacerbated caerulein-induced pancreatitis from edematous to hemorrhagic only when the obstruction preceded caerulein administration. The amylase secretion from the acini was inhibited, and intracellular trypsin activation and the acinar cell fragility on the supramaximal stimulation with cholecystokinin in vitro were enhanced by the preceding in vivo biliopancreatic duct obstruction.. Preceding biliopancreatic duct obstruction exacerbates caerulein-induced pancreatitis. Enhancement of intracellular trypsin activation is possibly involved in this mechanism.

Topics: Amylases; Animals; Ceruletide; Cholecystokinin; Cholestasis; Constriction, Pathologic; Disease Models, Animal; Disease Progression; Hemorrhage; In Vitro Techniques; Male; Pancreas; Pancreatic Ducts; Pancreatitis; Rats; Rats, Wistar; Trypsin

To illustrate the existence of bile regurgitation under stress condition, and explore the possible effects and related mechanism of changes of plasma cholecystokinin octapeptide (CCK-8) and intragastric pH on stress-induced bile regurgitation in rats.. (1) Changes in plasma CCK-8 and gastric bile concentration were respectively measured by using radioimmunoassay (RIA) method while simultaneously calculating gastric ulcer index (UI) and intragastric pH; (2) Each isolated gastric strips were suspended in a tissue chamber to record the contractile responses by polyphysiograph; (3) The responsiveness of gastric smooth muscle cells (SMCs) to sulfated cholecystokinin octapeptide (CCK-8S) were examined using fura-2-loaded microfluorimetric measurement of intracellular calcium concentration ([Ca(2+)]i); (4) The current of L-type calcium channels (I(CaL)) of SMCs were recorded by patch clamp techniques.. (1) Compared with the normal control group, plasma CCK-8 and gastric bile concentration significantly increased during stress (p<0.01) and both simultaneously reached the peak at the time point of 2 h after stress; UI and intragastric pH apparently increased (p<0.01); (2) Significant changes to CCK-8S were found in the mean contractile amplitude and frequency of circular muscle (CM) and longitudinal muscle (LM) of gastric antrum and pylorus; (3) CCK-8S-evoked significant increase in [Ca(2+)]i (p<0.01) could be suppressed by CCK-A receptor (CCK-AR) antagonist; whereas a small but significant increase was still elicited by CCK-8S under condition of the removal of extracellular calcium or by given nifidipine; (4) CCK-8S-intensified calcium current (I(CaL)) apparently inhibited by respective administration of nifidipine, Ca(2+)-ATPase inhibitors or calcium dependent chloride channel (I(Cl-Ca)) blocker (p<0.01).. Gastric mucosal damage induced by bile regurgitation is closely connected with gastric antrum and pylorus dysmotility evoked by CCK-8 during the stress. CCK-8S-evoked [Ca(2+)]i increase in gastric antrum and pylorus SMC depends on the release of intracellular calcium stores which activates L-type voltage-dependent calcium channels (VDCC) through the activation of calcium dependent chloride channels.

Topics: Animals; Bile; Calcium; Cholecystokinin; Digestive System; Disease Models, Animal; Female; Gastric Mucosa; Hydrogen-Ion Concentration; Male; Patch-Clamp Techniques; Peptide Fragments; Rats; Rats, Sprague-Dawley; Stomach Diseases; Ulcer

Neuropeptide cholecystokinin (CCK) interacts with dopamine in the regulation of motor activity and motivations. Therefore, in CCK(2) receptor deficient mice the behavioural effects of repeated amphetamine administration and changes in dopamine-related gene expression were studied. Four-day amphetamine (1 mg/kg) treatment induced a significantly stronger motor sensitization in homozygous mice compared to their wild-type littermates. However, in the conditioned place preference test the action of amphetamine was more pronounced in wild-type animals. As opposed to wild-type mice, amphetamine (1-3 mg/kg) did not cause a significant conditioned place preference in homozygous mice. The expression of Tyhy gene was elevated in the mesolimbic structures and Drd2 gene was down-regulated in the mesencephalon of saline-treated homozygous mice in comparison with respective wild-type group. Four-day treatment with amphetamine induced a significant increase in the expression of Tyhy in the mesencephalon, striatum and mesolimbic structures of wild-type mice, whereas in homozygous mice a similar change was evident only in the mesencephalon. Also, the expression of Drd1 gene in the striatum and Drd2 gene in the mesolimbic structures of wild-type mice were up-regulated under the influence of amphetamine. In conclusion, the present study established differences in the behavioural effects of amphetamine in wild-type and homozygous mice. The increased tone of dopaminergic projections from the mesencephalon to mesolimbic structures is probably related to increased amphetamine-induced motor sensitization in homozygous mice. The lack of development of up-regulation of Drd1 and Drd2 genes after repeated treatment with amphetamine probably explains the reduced place conditioning in CCK(2) receptor deficient mice.

Topics: Amphetamine; Amphetamine-Related Disorders; Animals; Behavior, Animal; Brain; Cholecystokinin; Conditioning, Psychological; Disease Models, Animal; Dopamine; Dopamine Uptake Inhibitors; Gene Expression Regulation; Homozygote; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Neural Pathways; Nucleus Accumbens; Receptor, Cholecystokinin B; Receptors, Dopamine; Tyrosine 3-Monooxygenase; Up-Regulation; Ventral Tegmental Area

Ulcerative colitis is associated with altered contractile activity and transit time of colon. On the other hand, cholecystokinin (CCK) has been shown to play an important role in regulation of gastrointestinal motor function including colonic contraction and transit. In the present study, an attempt was made to study the effect of proglumide, a CCK receptor antagonist on experimental colitis in rats. Experimental colitis was induced in male Sprague-Dawley rats by instilling 1 ml of 4% acetic acid followed by flushing with 0.5 ml air. The rats were kept in a head-down position for 30s. Finally, each rat received 1.5 ml colonic wash with 1.5 ml saline. Four groups of rats received proglumide orally (0, 250, 500 and 1000mg/kg). The first dose of proglumide was given 1 h before acetic acid challenge, whereas the second dose of proglumide was given 25 h after the first dose. Sham control rats received an equal volume of saline instead of acetic acid. Forty-eight hours after the acetic acid challenge, the colon was removed, weighed and split longitudinally and scored for injury. Part of the colon was used for histopathological study as well as analysis of myeloperoxidase (MPO) activity (as a marker of neutrophil activity). Acetic acid produced severe diarrhea and exfoliation of the colonic epithelium accompanied by extensive destruction of the mucosal interstitium. Proglumide dose dependently protected rats against acetic acid-induced increase in colon weight, diarrhea, MPO activity and colonic injury. Inhibition of CCK exerts a beneficial effect in experimental colitis. Further studies are warranted to determine the mechanism of protection and the therapeutic potential of CCK inhibitors.

Topics: Acetic Acid; Animals; Anti-Ulcer Agents; Cholecystokinin; Colitis, Ulcerative; Disease Models, Animal; Dose-Response Relationship, Drug; Indicators and Reagents; Male; Peroxidase; Proglumide; Rats; Rats, Sprague-Dawley

It is generally accepted that neuropathic pain is resistant to amelioration by morphine in clinical studies and insensitivity to intrathecal (i.t.) administered morphine in experimental models of neuropathic pain has been demonstrated. This study is to determine if endogenous dynorphin, substance P or cholecystokinin is involved in the lack of anti-allodynia of morphine in a partial sciatic nerve ligation (PSL) model of CD-1 mice. Mice exhibited tactile allodynia in the ipsilateral hind paw 1 day after PSL, and reached its maximal allodynic effect at 2 days and remained allodynic for 7 days. Morphine (3.0 nmol) given i.t. did not alter the tactile allodynic threshold in ipsilateral paw of mice pretreated i.t. with normal rabbit serum 2 days after PSL. However, the same dose of morphine (3.0 nmol) given i.t. reduced markedly allodynia in mice pretreated for 2h with antiserum against dynorphin A(1-17) (200 microg); the morphine-produced anti-allodynia developed slowly, reached its peak effect at 30 min and returned to an allodynic state in 60 min. Similarly, i.t. injection of morphine reduced the allodynia in PSL mice pretreated with antiserum against substance P (10 microg) or cholecystokinin (200 microg) for 2h. Intrathecal pretreatment with antiserum against dynorphin A(1-17), substance P or cholecystokinin for 2h injected alone did not affect the baseline mechanical tactile threshold in ipsilateral paw 2 days after PSL. The results indicate that endogenous dynorphin A(1-17), substance P and cholecystokinin are involved in PSL-induced neuropathic allodynia to attenuate the anti-allodynic effect of morphine.

Topics: Analgesics, Opioid; Animals; Antibodies; Cholecystokinin; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Resistance; Drug Synergism; Dynorphins; Immune Sera; Injections, Spinal; Ligation; Male; Mice; Morphine; Neuralgia; Peripheral Nervous System Diseases; Sciatic Nerve; Sciatic Neuropathy; Substance P

Cholecystokinin (CCK) has been implicated in anxiety disorders. The midbrain periaqueductal gray (PAG), which modulates anxiety and panic reactions, contains CCK-immunoreactive fibers and CCK(2) receptors. The present study investigated the involvement of CCK(2) receptors of the PAG dorsolateral subdivision (dlPAG) in the regulation of inhibitory avoidance and escape, two defensive behaviors that have been related in terms of psychopathology to generalized-anxiety and panic disorders, respectively. Male Wistar rats were microinjected in the dlPAG with the CCK(2) receptor agonist cholecystokinin-tetrapeptide (CCK-4; 0.08-0.32 nmol/0.2 microL), the CCK(2) receptor antagonist LY-225910 (0.05-0.20 nmol/0.2 microL) or LY-225910 prior to CCK-4. Inhibitory avoidance and escape behaviors were evaluated in the elevated T-maze. Whereas CCK-4 facilitated escape, indicating a panic-like action, LY-225910 had the opposite effect. Pretreatment with a non-effective dose of LY-225910 prevented the panic-eliciting action of CCK-4. Neither CCK-4 nor LY-225910 affected inhibitory avoidance acquisition. The present results substantiate the view that dlPAG CCK(2) receptors modulate panic-related behaviors.

Topics: Animals; Avoidance Learning; Behavior, Animal; Cholecystokinin; Disease Models, Animal; Exploratory Behavior; Fear; Male; Maze Learning; Motor Activity; Neural Pathways; Panic Disorder; Periaqueductal Gray; Quinazolines; Quinazolinones; Rats; Rats, Wistar; Receptor, Cholecystokinin B; Tetragastrin

The pharmacological profile of the new CCK1 receptor antagonist IQM-97,423, (4aS,5R)-2-benzyl-5-(tert-butylaminocarbonyl-tryptophyl)amino-1,3-dioxoperhydropyrido-[1,2-c]pyrimidine, was examined in in vitro and in vivo studies and compared with typical CCK1 antagonists such as devazepide and lorglumide. IQM-97,423 showed a high affinity at [3H]-pCCK8-labeled rat pancreatic CCK1 receptors, and was virtually devoid of affinity at brain CCK2 receptors. IQM-97,423 antagonized CCK8S-stimulated alpha-amylase release from rat pancreatic acini with a potency similar to devazepide and much higher than lorglumide. In the guinea pig isolated longitudinal muscle-myenteric plexus preparation, IQM-97,423 produced a full antagonism of the contractile response elicited by CCK8S and a weaker effect on the contraction elicited by CCK4, suggesting a selective antagonism at CCK1 receptors. The protective effect of IQM-97,423 and devazepide was tested in two models of acute pancreatitis in rats, induced by injection of cerulein or by combined bile and pancreatic duct obstruction. The new compound fully prevented the cerulein-induced increase in plasma pancreatic enzymes and in pancreas weight with a potency similar to devazepide. In common bile-pancreatic duct ligature-induced acute pancreatitis, IQM-97,423 partially prevented, like devazepide, the increase in plasma pancreatic enzyme activity and in pancreas weight. Consequently, the pyridopyrimidine derivative IQM-97,423 is a potent and highly selective CCK1 receptor antagonist with preventive effects in two experimental models of acute pancreatitis and a potential therapeutic interest.

Topics: Acute Disease; alpha-Amylases; Animals; Binding, Competitive; Cerebral Cortex; Cholecystokinin; Devazepide; Disease Models, Animal; Guinea Pigs; Ileum; In Vitro Techniques; Male; Mice; Muscle Contraction; Muscle, Smooth; Myenteric Plexus; Neuromuscular Junction; Pancreatitis; Peptide Fragments; Proglumide; Pyrimidinones; Rats; Rats, Wistar; Receptor, Cholecystokinin A

Using an original model, the donor rat model, we previously showed that bile-pancreatic juice exclusion from gut exacerbates ligation-induced acute pancreatitis. Here, we examine the mechanism by which bile-pancreatic juice exclusion from gut exacerbates acute pancreatitis. In the first part of the study we test the hypothesis that Na taurocholate and trypsin are components of bile-pancreatic juice that exacerbate acute pancreatitis when excluded. Our experiments show that combined replacement of Na taurocholate and trypsin ameliorates acute pancreatitis. In the second part of the study we test the hypothesis that bile-pancreatic juice exclusion from gut exacerbates acute pancreatitis via combined CCK-A and cholinergic receptor pathways. Our experiments show that combined CCK-A and cholinergic receptor blockade significantly ameliorates acute pancreatitis while blockade of either receptor alone does not. We conclude that bile-pancreatic juice exclusion-induced exacerbation of ligation-induced acute pancreatitis involves a neurohormonal duodenal response to exclusion of trypsin and Na taurocholate resulting in acinar cell hyperstimulation via combined CCK-A and cholinergic receptor-mediated pathways.

Topics: Amylases; Animals; Bile; Bile Ducts; Cholecystokinin; Disease Models, Animal; Male; Pancreatic Juice; Pancreatitis; Rats; Rats, Sprague-Dawley; Taurocholic Acid; Trypsin

Several human and animal studies indicate that the anterior cingulate cortex (ACC) plays an important role in the affective component of pain. The neuropeptide cholecystokinin (CCK) is especially abundant in the ACC. CCK has been suggested to be involved in the mediation of anxiety and in the modulation of opioid effects in the spinal cord and medulla oblongata. However, its possible role in pain transmission or modulation in the brain is far less clear. In this study, a model of subchronic inflammatory pain in rats, carrageenan-induced monoarthritis, was used to study the effect of pain on the release of CCK-like immunoreactivity (CCK-LI) in the ACC. Pain-related behaviour quantified by weight bearing and stance scoring, as well as inflammation measured by ankle oedema, was increased for at least 24 h after carrageenan injection with a maximum at 5 h. Using microdialysis in freely moving rats, extracellular concentrations of CCK-LI was measured in the ACC during a time period when the animals showed significant pain behaviour. In animals with carrageenan-induced arthritis, both basal and potassium-evoked release of CCK-LI were significantly increased compared to controls. HPLC analysis of dialysates from the ACC during potassium stimulation showed that the main part of the immunoreactive material was sulphated CCK-8. Because CCK has been implicated in anxiety, we suggest that an altered CCK-ergic activity in the ACC may be of importance for the affective component of pain, but an involvement in the modulation of nociception is also possible.

Topics: Analysis of Variance; Animals; Arthritis; Behavior, Animal; Calcium; Carrageenan; Cholecystokinin; Chromatography, High Pressure Liquid; Disease Models, Animal; Functional Laterality; Gyrus Cinguli; Male; Microdialysis; Pain Measurement; Potassium; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Time Factors; Weight-Bearing

Niemann-Pick disease type C (NP-C) is a progressive neurological disorder of lipid metabolism. The Balb/C npc1 mutant strain is a genetically authentic murine model of NPC, which reproduce the clinical and histologic features of human NP-C. In the present study, we show that cholecystokinin (CCK)-immunoreactive fibers in the thalamic VPL nuclei, which are densely distributed in controls, degenerate in NPC mice. This degeneration is associated with the appearance of CCK-immunoreactive axonal spheroids containing characteristic intracellular inclusions of NP-C. These observations provide supportive evidence of the occurrence of dying-back axonopathy of neurons in the dorsal column nuclei in this mouse model.

Topics: Afferent Pathways; Animals; Axons; Cholecystokinin; Disease Models, Animal; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Mice; Mice, Inbred BALB C; Mice, Mutant Strains; Microscopy, Immunoelectron; Nerve Degeneration; Neurons; Niemann-Pick C1 Protein; Niemann-Pick Diseases; Proteins; Ventral Thalamic Nuclei

Biologic data related to pancreatic regeneration and acinar-cell homeostasis after ductal decompression would be useful in clinical settings to elucidate the time at which obstructions in human biliary acute pancreatitis (AP) should be removed. Our aim was to evaluate the outcome of AP after early removal of bile-pancreatic-duct obstruction (BPDO) and to ascertain whether cholecystokinin (CCK) blockade accelerates recovery from the disease. We conducted analysis of apoptosis and cell cycle, as well as measurements of enzyme and calcium load, in acinar cells using flow cytometry to ascertain the capability of the pancreas to regain its function after AP. Male Wistar rats were subjected to AP by means of BPDO for 6 hours and 24 hours. In other groups, the BPDO was opened 24 hours after induction; 3 days and 7 days later they were killed. Half of the rats in which the BPDO was opened were administered L364,718, a CCK-receptor antagonist (0.1 mg/kg/12 hours), 30 minutes before the induction of BPDO. Plasma amylase activity, hematocrit, and pancreatic weight returned to control values after BPDO opening. The highest degree of oxidative stress was found in the pancreases of rats subjected to BPDO for 6 hours, as indicated by the decrease in pancreatic glutathione content, but it was not restored 7 days after BPDO opening. Cell-cycle distribution, as measured with propidium iodide DNA staining, showed increases in the proportion of acinar cells in S-phase from 3 days after BPDO opening in L364,718-treated and nontreated rats. Annexin V-fluorescein isothiocyanate labeling revealed deletion of acinar cells by way of apoptosis 3 days after BPDO opening. However, it may be compensated 7 days after BPDO opening because regardless of whether rats were treated with L364,718, significant increases in synthesis and mitosis were detected. Accumulation of digestive enzymes and calcium in acinar cells was found during BPDO, but this appeared to have normalized 3 days after BPDO opening and onward in both L364,718-treated and nontreated rats. In conclusion, early removal of obstruction allowed rapid cell proliferation and prevented the progression of severe alterations within acinar cells induced by BPDO. CCK blockade does not accelerate pancreatic recovery after BPDO opening.

Topics: Acute Disease; Amylases; Animals; Apoptosis; Calcium; Cell Cycle; Cholecystokinin; Cholestasis, Extrahepatic; Decompression, Surgical; Devazepide; Disease Models, Animal; Flow Cytometry; Hormone Antagonists; Male; Pancreas; Pancreatic Ducts; Pancreatitis; Rats; Rats, Wistar; Time Factors; Trypsinogen

Cholecystokinin (CCK) in the CNS antagonizes the opioid system and has been implicated post-spinal cord injury (SCI) pain. The current study found that excitotoxic SCI alters levels of CCK mRNA levels in the cortex, diencepahlon, and mesencephalon of rats. Animals that developed pain post-SCI had significantly higher levels than animals that did not develop pain. Upregulation of CCK mRNA in the cortex may be related to post-SCI pain in rats.

Topics: Animals; Behavior, Animal; Cerebral Cortex; Cholecystokinin; Diencephalon; Disease Models, Animal; Efferent Pathways; Grooming; Gyrus Cinguli; Mesencephalon; Neuronal Plasticity; Neurons; Opioid Peptides; Pain; Rats; RNA, Messenger; Spinal Cord Injuries; Up-Regulation

Alterations of gamma-aminobutyric acid (GABA)B receptor expression have been reported in human temporal lobe epilepsy (TLE). Here, changes in regional and cellular expression of the GABAB receptor subunits R1 (GBR1) and R2 (GBR2) were investigated in a mouse model that replicates major functional and histopathological features of TLE. Adult mice received a single, unilateral injection of kainic acid (KA) into the dorsal hippocampus, and GABAB receptor immunoreactivity was analysed between 1 day and 3 months thereafter. In control mice, GBR1 and GBR2 were distributed uniformly across the dendritic layers of CA1-CA3 and dentate gyrus. In addition, some interneurons were labelled selectively for GBR1. At 1 day post-KA, staining for both GBR1 and GBR2 was profoundly reduced in CA1, CA3c and the hilus, and no interneurons were visible anymore. At later stages, the loss of GABAB receptors persisted in CA1 and CA3, whereas staining increased gradually in dentate gyrus granule cells, which become dispersed in this model. Most strikingly, a subpopulation of strongly labelled interneurons reappeared, mainly in the hilus and CA3 starting at 1 week post-KA. In double-staining experiments, these cells were selectively labelled for neuropeptide Y. The number of GBR1-positive interneurons also increased contralaterally in the hilus. The rapid KA-induced loss of GABAB receptors might contribute to epileptogenesis because of a reduction in both presynaptic control of transmitter release and postsynaptic inhibition. In turn, the long-term increase in GABAB receptors in granule cells and specific subtypes of interneurons may represent a compensatory response to recurrent seizures.

Topics: Animals; Cell Count; Cholecystokinin; Disease Models, Animal; Epilepsy, Temporal Lobe; Excitatory Amino Acid Agonists; Hippocampus; Immunohistochemistry; Kainic Acid; Male; Mice; Neuropeptide Y; Receptors, GABA-B; Somatostatin; Time; Time Factors

The effects of estradiol benzoate (EB) on gastric emptying, gastrointestinal transit and plasma levels of cholecystokinin (CCK) were studied in ovariectomized rats.. Gastrointestinal motility was assessed in rats 15 min after intragastric instillation of a test meal containing charcoal and Na2 51CrO4. Gastric emptying was determined by measuring the amount of radiolabeled chromium contained in the small intestine as a percentage of the initial amount received. Gastrointestinal transit was evaluated by calculating the geometric center of distribution of the radiolabeled marker. Blood samples were collected for E2 and CCK radioimmunoassay.. After treatment of EB (4-25 microg/kg), gastric emptying and gastrointestinal transit were inhibited, whereas plasma concentrations of E2 and CCK were increased in a dose-dependent manner. The selective CCK(A) receptor antagonists, devazepide and lorglumide, effectively attenuated the EB-induced inhibition of gastric emptying and gastrointestinal transit. L-365,260, a selective CCK(B) receptor antagonist, did not alter the EB-induced inhibition of gastric emptying and gastrointestinal transit.. The results suggest that EB inhibits gastric emptying and gastrointestinal transit in ovariectomized rats via a mechanism involving CCK stimulation and CCK(A) receptor activation.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Disease Models, Animal; Estradiol; Female; Gastric Emptying; Gastrointestinal Transit; Hormone Antagonists; Ovariectomy; Phenylurea Compounds; Proglumide; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Time Factors

The distribution of mRNAs encoding for somatostatin, cholecystokinin and neuropeptide Y was determined by in situ hybridization histochemistry in the weaver (wv/wv) mouse, a model of dopamine deficiency as well as in normal (+/+) controls. Weaver mutants did not show any appreciable departure from the normal pattern of expression for mRNA encoding for neuropeptide Y. In contrast, an 82% increase in mRNA encoding for somatostatin was observed in the reticular thalamic nucleus, whereas increases in the order of 20-87% were observed in different hypothalamic nuclei of the weaver brain. In addition, a 47-103% increase of the hybridization signal encoding for cholecystokinin was observed in the cerebral cortex, hippocampus and thalamus of the weaver brain. It can be assumed that the elevated and region-specific somatostatin and cholecystokinin levels observed in the weaver brain may be due to a secondary or compensatory response under conditions of altered neurotransmitter levels.

Topics: Animals; Brain; Cholecystokinin; Disease Models, Animal; Dopamine; In Situ Hybridization; Mice; Mice, Neurologic Mutants; Neuropeptide Y; RNA, Messenger; Somatostatin; Up-Regulation

It is hypothesized that cholecystokinin stimulates acid secretion directly and indirectly by binding to CCK-2 (CCK-B/gastrin) receptors on both parietal and enterochromaffin-like cells. At the same time, however, it inhibits acid responses by stimulating the paracrine secretion of somatostatin from D cells and thereby exerts a tonic inhibition on the parietal cells. To test the validity of this hypothesis, we determined gastric acid secretion in the CCK-1 (CCK-A) receptor-deficient Otsuka Long-Evans Tokushima fatty (OLETF) rats.. Gastric acid secretion was determined in the acute fistula OLETF and the control Long-Evans Tokushima Otsuka (LETO) rats. Plasma concentrations of gastrin, CCK, somatostatin and histamine were determined by radioimmunoassay. The levels of CCK-2 receptor mRNA in the mucosa of the glandular stomach were determined by Northern blot analysis.. Pentagastrin- and CCK-8-stimulated as well as basal acid outputs in OLETF rats were significantly higher than those in LETO rats. CCK-2 receptor antagonist reduced basal acid outputs and completely suppressed CCK-8-stimulated acid secretion in both strains. CCK-8 enhanced the pentagastrin-stimulated gastric acid output in OLETF rats, but not in LETO rats. In LETO rats, CCK-1 receptor antagonist increased CCK-8-stimulated gastric acid secretions to those in OLETF rats. The level of CCK-2 receptor mRNA in the stomach in OLETF rats was 2-fold higher than that in LETO rats. In OLETF rats, plasma concentrations of CCK and histamine were higher, whereas somatostatin concentrations were lower than those in LETO rats, with no change in basal plasma gastrin concentrations.. These results in the CCK-1 receptor-deficient OLETF rats confirmed that CCK stimulates acid secretion by binding to CCK-2 receptors, but at the same time inhibits acid responses by stimulating the paracrine secretion of somatostatin from D cells in the gastric mucosa.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Gastric Acid; Gastrins; Histamine; Male; Paracrine Communication; Parietal Cells, Gastric; Rats; Rats, Inbred OLETF; Receptor, Cholecystokinin A; Receptors, Cholecystokinin; Somatostatin; Somatostatin-Secreting Cells

Cholecystokinin (CCK) is co-localized with dopamine, is known to modulate dopamine neurotransmission and is involved in behavioral sensitization to psychostimulants. To better understand its role, CCK was measured by microdialysis in the nucleus accumbens (NAC) shell in response to cocaine in drug-naive rats and in rats that are behaviorally sensitized to cocaine. Basal extracellular levels of CCK in drug-naive rats were 0.17 pg/20 min fraction, while in cocaine-sensitized rats, they were significantly higher (0.56 pg). Treating drug-naive rats with cocaine caused a significant increase in CCK to 0.58 pg. Cocaine treatment of cocaine-sensitized rats increased CCK to 0.98. When analyzed as a function of time after cocaine treatment, these increases were sustained and were significantly different from CCK levels of saline-treated rats. In cocaine-sensitized rats, CCK levels following cocaine treatment were also significantly higher than levels in drug-naive animals receiving a single injection of cocaine. These results provide evidence for an activation of the mesolimbic and/or cerebral cortical CCK system in response to repeated cocaine administration. These results provide a neurochemical basis for an important role of CCK (via modulation of dopamine neurotransmission) in expression of cocaine sensitization.

Topics: Animals; Behavior, Animal; Cholecystokinin; Chromatography, High Pressure Liquid; Cocaine; Cocaine-Related Disorders; Disease Models, Animal; Extracellular Space; Injections, Intraperitoneal; Male; Microdialysis; Motor Activity; Nucleus Accumbens; Rats; Rats, Sprague-Dawley; Time Factors; Wakefulness

The involvement of cholecystokinin (CCK) in the mechanisms of stress and/or anxiety was assessed by in vivo microdialysis in rats subjected to a social stress paradigm. During the initial 30 min period of each conditioning session, a male Sprague Dawley rat (intruder) was placed in a protective cage inside the cage of a male Tryon Maze Dull rat (resident), allowing unrestricted visual, olfactory, and auditory contacts but precluding close physical contact between them. During the following 15 min period, both the protective cage and the resident were removed (nondefeated intruders) or only the protective cage was removed allowing the resident to attack the intruder (defeated rats). This procedure was repeated once daily for 4 d. On the fifth day, a guide cannula was implanted into the prefrontal cortex of intruders. During a single 30 min test session, performed 4 d later, intruders were subjected to only the 30 min protected confrontation to the resident. Anxiety-like behavior (immobility, ultrasonic vocalizations, and defensive postures), associated with an increase (approximately +100% above baseline) in cortical outflow of CCK-like material (CCKLM), were observed in defeated intruders. Pretreatment with diazepam (5 mg/kg, i.p.), but not buspirone (0.5-2 mg/kg, i.p.), prevented both the anxiety-related behavior and CCKLM overflow. The selective CCK-B receptor antagonist CI-988 (2 mg/kg, i.p.) reduced the anxiety-like behavior without affecting the increase in CCKLM outflow. These data indicate that anticipation of social defeat induces a marked activation of cortical CCKergic neurons associated with anxiety-related behaviors in rats.

Topics: Aggression; Animals; Anti-Anxiety Agents; Anxiety; Behavior, Animal; Cholecystokinin; Conditioning, Psychological; Disease Models, Animal; Dominance-Subordination; Electrodes, Implanted; Extracellular Space; Male; Microdialysis; Motor Activity; Prefrontal Cortex; Rats; Rats, Inbred Strains; Rats, Sprague-Dawley; Stress, Physiological; Territoriality

We compared the antinociceptive activity of a kappa-opioid agonist, U-50488H, in streptozotocin-induced diabetic mice with that in non-diabetic mice. Subcutaneously administered U-50488H (3 and 10 mg kg(-1)) showed a more potent antinociceptive effect, as evaluated by the tail-pressure method, in diabetic mice than in non-diabetic mice. Increased antinociceptive activity of U-50488H observed in diabetic mice was also observed in mice given U-50488H intrathecally (3 and 10 microg). However, there were no differences observed between diabetic and non-diabetic mice given U-50488H intracerebroventricularly (3 and 10 microg). Although the antinociceptive effect of U-50488H (3 mg kg(-1), s.c.) in non-diabetic mice was increased by treatment with PD135158 (100 ng, i.c.v.), a cholecystokininB (CCKB) antagonist, the antinociceptive activity of U-50488H which was enhanced in diabetic mice was not influenced by PD135158. Moreover, the increased antinociceptive activity of U-50488H (3 mg kg(-1), s.c.) in diabetic mice diminished when desulfated octapeptide of cholecystokinin (3-100 ng, i.c.v.), a CCKB agonist, was administered. These results suggested that diabetic mice were selectively hyper-responsive to spinal kappa-opioid receptor-mediated antinociception. The function of the analgesia inhibitory system in which cholecystokinin is used as a transmitter might be diminished in diabetic mice.

Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Analgesics; Analgesics, Non-Narcotic; Animals; Anti-Bacterial Agents; Cholecystokinin; Diabetes Mellitus; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Mice; Pain; Streptozocin

D(1)-like (D(1), D(5)) and D(2)-like (D(2), D(3), D(4)) dopamine receptors interact in the kidney to produce a natriuresis and a diuresis. Disruption of D(1) or D(3) receptors in mice results in hypertension that is caused, in part, by a decreased ability to excrete an acute saline load. We studied D(1)-like and D(2)-like receptor interaction in anesthetized spontaneously hypertensive rats (SHR) by the intrarenal infusion of Z-1046 (a novel dopamine receptor agonist with rank order potency of D(3)> or =D(4)>D(2)>D(5)>D(1)). Z-1046 increased glomerular filtration rate (GFR), urine flow, and sodium excretion in normotensive Wistar-Kyoto rats but not in SHRs. The lack of responsiveness to Z-1046 in SHRs was not an epiphenomenon, because intrarenal cholecystokinin infusion increased GFR, urine flow, and sodium excretion to a similar extent in the two rat strains. We conclude that renal D(1)-like and D(2)-like receptor interaction is impaired in SHRs. The impaired D(1)-like and D(2)-like receptor interaction in SHRs is not caused by alterations in the coding sequence of the D(3) receptor, the D(2)-like receptor expressed in rat renal tubules that has been shown to be involved in sodium transport. Because the diuretic and natriuretic effects of D(1)-like receptors are, in part, caused by an interaction with D(2)-like receptors, it is possible that the decreased Z-1046 action in SHRs is secondary to the renal D(1)-like receptor dysfunction in this rat strain.

Topics: Animals; Biological Transport; Cholecystokinin; Disease Models, Animal; Diuresis; Dopamine Agonists; Glomerular Filtration Rate; Hypertension; Infusions, Intra-Arterial; Kidney; Kidney Function Tests; Male; Naphthols; Natriuresis; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptors, Dopamine D1; Receptors, Dopamine D2; Receptors, Dopamine D3; Sequence Analysis, DNA; Sodium

We examined the influence of 2 gut hormones involved in the enhancement of pancreatic exocrine secretion, secretin and cholecystokinin (CCK), in the exacerbation of pancreatitis. We also examined the role of the vagal system, which was considered to be a transmission route for these hormones. Our model of pancreatitis in the rat was prepared by pancreatic bile duct ligation (PBDL), which simultaneously ligated the pancreatic duct and the common bile duct. Serum amylase activity and histopathological changes in the pancreas were used as indices of pancreatitis. We also measured the volume of pancreatic juice, as well as the amylase activity and protein level of the pancreatic juice, as indices of increased pancreatic exocrine secretion. Two gut hormones were given 6 times at 1-h intervals. Administration of secretin (1-3 microg/kg, s.c.) did not influence serum amylase activity in rats with PBDL-induced pancreatitis. However, food stimulation and administration of CCK-8 (1 microg/kg, s.c.) increased serum amylase activity and promoted vacuolation of the pancreatic acinar cells in rats with PBDL-induced pancreatitis. Administration of atropine (3 mg/kg, s.c.) or a CCK1-receptor antagonist, Z-203 (0.1 mg/kg, i.v.), inhibited food-stimulated or CCK-8-induced (1 microg/kg, s.c.) enhancement of pancreatic exocrine secretion and exacerbation after the development of PBDL-induced pancreatitis. These results suggest that not secretin, which regulates the volume of pancreatic juice, but CCK, which regulates the secretion of pancreatic enzymes via the vagal system, plays an essential role in food-stimulated exacerbation after the development of pancreatitis.

Topics: Amylases; Animals; Bile Ducts; Cholecystokinin; Disease Models, Animal; Fasting; Ligation; Male; Pancreas; Pancreatitis; Rats; Secretin; Sincalide; Vagus Nerve

Evidence based on animal studies suggests that cholecystokinin (CCK) is involved in the induction and development of acute experimental pancreatitis. However, the results obtained with CCK or CCKA receptor antagonists in different species (rats, mice) and different models of acute pancreatitis (cerulein pancreatitis, hemorrhagic pancreatitis induced by choline-deficient, ethionine-supplemented diet, arginine-induced pancreatitis, sodium taurocholate-induced pancreatitis) produced variable results. The route of administration, the specificity and potency of compounds and the design of the study are predictive for the outcome. Based on the available information, CCK appears to play a contributory role in the development of acute experimental pancreatitis in mice and rats. No conclusions can be drawn from these results with respect to the human disease.

Topics: Acute Disease; Animals; Cholecystokinin; Disease Models, Animal; Humans; Mice; Pancreatitis; Rats; Receptors, Cholecystokinin

This presentation reviews the role of cholecystokinin (CCK) as a contributory factor for the development and progression of acute pancreatitis (AP) and the perspective of CCK receptor antagonists for treatment of AP. High, supraphysiological concentrations of CCK induce AP in various species including man. There is also evidence that physiological increases in plasma CCK deteriorates AP in several animal models. The latter findings support the hypothesis that CCK plays a contributory or permissive role for the development of AP. The majorities of experimental studies show that the prophylactic and therapeutic use of CCK antagonists ameliorates AP. The latter effects were clearly shown for models of biliary AP in which plasma CCK is increased due to a feedback mechanism. However, CCK antagonists also had beneficial effects in models in which plasma CCK is not increased. In animal strains which do not have a CCK-A-receptor due to a genetic abnormality AP induced by a certain noxious factor does not develop to the same severity when compared to animals with a normal CCK-A-receptor. Thus, CCK acts as a permissive or contributory factor for the development and progression of AP. There is also evidence that CCK antagonists have a potential therapeutic benefit. Clinical studies will evaluate their therapeutic potential for patients with AP.

Topics: Acute Disease; Animals; Ceruletide; Cholecystokinin; Devazepide; Disease Models, Animal; Disease Progression; Humans; Indoles; Pancreatitis; Rats; Receptors, Cholecystokinin

Topics: Animals; Cholecystokinin; Disease Models, Animal; Ethanol; Female; Humans; Male; Pancreas; Pancreatitis, Alcoholic; Risk Factors

We compared pancreatic exocrine secretion in 5-month-old WBN/Kob rats, a model of chronic pancreatitis, with that in Wistar rats of the same age in a conscious state. Basal pancreatic secretion and pancreatic wet weight in WBN/Kob rats were lower than the values for Wistar rats. There was no difference in plasma cholecystokinin (CCK) concentration between the two types of rats. When CCK-8 was intravenously administered, the stimulation of pancreatic protein secretion in WBN/Kob rats was weaker than that in Wistar rats. When bile and pancreatic juice were diverted from the duodenum, the resulting increase in the plasma CCK concentration was similar in both types of rats, but stimulation of the volume and protein output of pancreatic juice in WBN/Kob rats was weaker than that in Wistar rats. In addition, WBN/Kob rats exhibited little increase in pancreatic wet weight because of this diversion. When secretin was intravenously administered, the stimulation of fluid secretion in WBN/ Kob rats was also weaker than that in Wistar rats. The binding of CCK-8 to pancreatic membrane fractions in WBN/Kob rats was much weaker than that in Wistar rats. Histological findings in WBN/Kob rat pancreas showed proliferation of fibrous tissue and atrophy of acinar cells. In conclusion, pancreatic exocrine secretion in response to the gastrointestinal hormones, CCK and secretin, was lower in WBN/Kob rats than in Wistar rats. These findings suggest that the hyposecretion of pancreas in WBN/Kob rats is hyporeaction of pancreatic membrane to gastrointestinal hormones.

Topics: Animals; Bile; Cholecystokinin; Chronic Disease; Disease Models, Animal; Male; Pancreas; Pancreatic Juice; Pancreatitis; Proteins; Rats; Rats, Wistar; Secretin; Sincalide

In order to elucidate the involvement of cholecystokinin (CCK) in the regulation of anxiety, the author examined the effects of the selective non-peptide CCKB receptor antagonist LY288513 on freezing behavior induced by conditioned fear stress, an animal model of anxiety. Rats were individually subjected to 5 min of inescapable electric footshock in a shock chamber. Twenty-four hours after the footshock, the rats were again placed in the shock chamber and observed for 5 min without shocks: this procedure is termed conditioned fear stress. Subcutaneous administration of LY288513 30 min before footshock (0.3 mg/kg) and 30 min before conditioned fear stress (0.03-0.3 mg/kg) reduced conditioned freezing. This indicates that LY288513 blocked both the acquisition and expression of conditioned fear. The relatively selective non-peptide CCKA receptor antagonist, lorglumide, blocked the expression of conditioned fear, but only at a high dose (1.0 mg/kg). The peripheral non-peptide CCKA/B receptor antagonist, loxiglumide, failed to do so. Subcutaneous administration of LY288513 (3 mg/kg) enhanced the conditioned fear-induced in 3, 4-dihydroxy-phenylacetic acid (DOPAC) contents in the medial prefrontal cortex, which was assayed by high performance liquid chromatography with electrochemical detection. Thirty min of inescapable electric footshock decreased CCK8S contents in the amygdala, which was assayed by radioimmunoassay. These results suggest that the brain CCKB receptors are involved in the regulation of anxiety, and that the anxiolytic effects of CCKB receptor antagonists are mediated by increasing dopamine activity in the medial prefrontal cortex. Furthermore, it is possible that the CCK neurons in the amygdala are also associated with anxiety.

Topics: Animals; Anxiety; Biogenic Monoamines; Brain; Cholecystokinin; Disease Models, Animal; Hormone Antagonists; Male; Proglumide; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Receptors, Cholecystokinin

The aim of the present study was determinate the role of nitric oxide (NO) in the action of CCK on arterial blood pressure and function of isolated rat heart. Intravenous administration of NO synthase (NOS) inhibitor-NG-nitro-L-arginine methyl ester (L-NAME-100.0 micrograms/kg) increased arterial blood pressure and abolished the hypertensive effect of CCK (administered in the highest dose: 425.0 pmoles/kg i.v.). Donors NO: L-arginine (L-Arg-100.0 mg/kg i.v.) and sodium nitroprusside (SNP-10.0 micrograms/kg i.v.) decreased arterial blood pressure, the hypotensive effect evoked by SNP was greater than produced by L-Arg. CCK administered with L-Arg evoked hypotension (opposite to the hypertensive effect evoked by CCK). When we used CCK at the higher doses (212.5; 425 pmoles/kg i.v.) simultaneously with L-Arg the hypotensive effect was greater than the hypotensive action evoked by L-Arg alone. Administration of CCK with SNP produced the hypotension (similar as after used SNP and opposite to the hypertensive action of the peptide). CCK (21.25, 42.5, 106.25 pmoles/0.1 ml) increased the cardiac contraction amplitude, the peptide injected in lower doses decreased coronary outflow. CCK had no effect on heart rate. L-NAME (10(-5) M) decreased coronary outflow, tendent to evoke bradycardia (p > 0.05) and the compound did not change the cardiac contraction amplitude of isolated heart. L-NAME abolished the influence of CCK on the function of isolated heart. L-Arg (10(-2) M) did not affect function of isolated heart. L-Arg abolished and when we used with CCK in the highest dose reversed the positive inotropic effect of the peptide and tendent to abolish a lowered coronary outflow evoked by CCK. SNP (10(-4) M) decreased the cardiac contraction amplitude. SNP diminished the positive inotropic effect of CCK and did not change other parameters of isolated heart.. NO does not play a role in cardiovascular action of CCK directly, however inhibitor of NO synthase and donors of NO change the influence of the peptide, mainly on the heart. We suggest that the effect is indirectly through catecholamines.

Topics: Analysis of Variance; Animals; Blood Pressure; Cardiovascular Physiological Phenomena; Catecholamines; Cholecystokinin; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Enzyme Inhibitors; Male; Myocardial Contraction; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Rats; Rats, Wistar; Reference Values

This study investigated the interplay of cholecystokinin (CCK) and endogenous opioid peptides in the regulation of anxiety. The acute administration of non-selective CCK agonist caerulein (1 and 5 microg/kg) and a selective CCK(B) receptor agonist BOC-CCK-4 (1, 10 and 50 microg/kg) induced a dose-dependent anxiogenic-like action in the plus-maze model of anxiety. BOC-CCK-4 displayed a similar efficacy with caerulein, indicating that the described effect was mediated via CCK(B) receptor subtype. The opioid antagonist naloxone itself (0.5 mg/kg) did not change the exploratory activity of rats in the plus-maze. However, the combination of naloxone with the sub-effective doses of caerulein (1 microg/kg) and BOC-CCK-4 (1 microg/kg) induced a significant inhibition of exploratory behaviour in rats. Accordingly, CCK and endogenous opioid peptides have an antagonistic role in the exploratory model of anxiety in rats.

Topics: Animals; Anxiety; Ceruletide; Cholecystokinin; Disease Models, Animal; Drug Synergism; Exploratory Behavior; Male; Naloxone; Narcotic Antagonists; Rats; Rats, Wistar; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Tetragastrin

To examine the effect of gastrin on spontaneous and induced pancreatic carcinogenesis in the hamster.. Two sets of experiments were carried out, one involving long term hypergastrinaemia and one involving cancer induction during hypergastrinaemia. The effect of hypergastrinaemia accomplished by gastric fundectomy was studied for eight months. Neither fundectomised hamsters nor sham operated controls developed premalignant or malignant pancreatic lesions. In the fundectomy group, the mean pancreatic weight, total protein content, and DNA content was increased by 28%, 25%, and 25% respectively. No such increases were found in fundectomised animals receiving a cholecystokinin-B receptor antagonist during the last 24 days of the experiment. In the cancer induction study, the effect of fundectomy on N-nitrosobis(2-oxopropyl) amine induced pancreatic carcinogenesis was studied for three months. There were no significant differences in the incidence or [3H]-thymidine labelling index of focal pancreatic lesions between fundectomised and sham operated control animals.. Fundectomy with chronic hypergastrinaemia induces pancreatic hypertrophy, but does not enhance N-nitrosobis (2-oxopropyl)amine induced pancreatic carcinogenesis in the hamster. The increases in growth were inhibited by a cholecystokinin-B receptor antagonist, indicating that the trophic effect of fundectomy is mediated by gastrin.

Topics: Animals; Benzodiazepinones; Carcinogens; Cholecystokinin; Cricetinae; Disease Models, Animal; Gastric Fundus; Gastrins; Hypertrophy; Male; Mesocricetus; Neoplasms, Experimental; Nitrosamines; Pancreas; Pancreatic Neoplasms; Phenylurea Compounds; Receptors, Cholecystokinin

1. The pyridopyrimidine derivative IQM-95,333 ((4aS,5R)-2-benzyl-5-[N alpha-tert-butoxicarbonyl)L-tryptophyl] amino-1,3dioxoperhydropyrido[1,2-c]pyrimidine), a new non-peptide antagonist of cholecystokinin type A (CCKA) receptors, has been evaluated in vitro and in vivo in comparison with typical CCKA and CCKB receptor antagonists, such as devazepide, lorglumide, L-365,260 and PD-135,158. 2. IQM-95,333 displaced [3H]-CCK-8S binding to CCKA receptors from rat pancreas with a high potency in the nanomolar range. Conversely, the affinity of this new compound at brain CCKB receptors was negligible (IC50 > 10 microM). IQM-95,333 was a more selective CCKA receptor ligand than devazepide and other CCKA receptor antagonists. 3. Like devazepide, IQM-95,333 was a more potent antagonist of CCK-8S- than of CCK-4-induced contraction of the longitudinal muscle from guinea-pig ileum, suggesting selective antagonism at CCKA receptors. 4. IQM-95,333 and devazepide were also potent inhibitors of CCK-8S-stimulated amylase release from isolated pancreatic acini, a CCKA receptor-mediated effect. The drug concentrations required (IC50s around 20 nM) were higher than in binding studies to pancreas homogenates. 5. Low doses (50-100 micrograms kg-1, i.p.) of IQM-95,333 and devazepide, without any intrinsic effect on food intake or locomotion, blocked the hypophagia and the hypolocomotion induced by systemic administration of CCK-8S, two effects associated with stimulation of peripheral CCKA receptors. 6. IQM-95,333 showed an anxiolytic-like profile in the light/dark exploration test in mice over a wide dose range (10-5,000 micrograms kg-1). Typical CCKA and CCKB antagonists, devazepide and L-365,260 respectively, were only effective within a more limited dose range. 7. In a classical conflict paradigm for the study of anxiolytic drugs, the punished-drinking test, IQM-95,333, devazepide and L-365,260 were effective within a narrow dose range. The dose-response curve for the three drugs was biphasic, suggesting that other mechanisms are operative at higher doses. 8. In conclusion, IQM-95,333 is a potent and selective CCKA receptor antagonist both in vitro and in vivo with an anxiolytic-like activity in two different animal models, which can only be attributed to blockade of this CCK receptor subtype.

Topics: Amylases; Animals; Anorexia; Anti-Anxiety Agents; Benzodiazepinones; Carbamates; Cholecystokinin; Devazepide; Diazepam; Disease Models, Animal; Fenfluramine; Guinea Pigs; Hormone Antagonists; Locomotion; Male; Mice; Phenylurea Compounds; Pyrimidinones; Rats; Rats, Wistar; Receptors, Cholecystokinin; Selective Serotonin Reuptake Inhibitors

The effect of oral administration of protease inhibitor (camostat) on pancreatic morphology and exocrine function (conscious rat model) was investigated using WBN/Kob rats with spontaneous chronic pancreatitis. In nontreated WBN/Kob rats (2-12 months of age), pancreatic fibrosis and parenchymal destruction compatible with human chronic pancreatitis appeared at 3 months and advanced with each month. Pancreatic secretion was markedly impaired at all ages. In WBN/Kob rats fed diets containing camostat (from 2-3 or 4-5 months of age), the pancreas was hypertrophic and did not show any histological appearances compatible with chronic pancreatitis, and moreover, exocrine function was thoroughly restored with increased plasma cholecystokinin concentrations. Oral administration of protease inhibitor has both preventive and therapeutic effects on pancreatic lesions and dysfunction in an animal model of chronic pancreatitis, probably via endogenous cholecystokinin release.

Topics: Administration, Oral; Animals; Cholecystokinin; Chronic Disease; Disease Models, Animal; Esters; Gabexate; Guanidines; Humans; Male; Pancreas; Pancreatitis; Protease Inhibitors; Rats; Rats, Inbred Strains; Rats, Wistar

The insulin-like growth factor (IGF) system has a role in repair following hypoxic-ischemic injury in many tissues including the brain. To study the involvement of the IGF system following head trauma, we used a rat contusion model, which produces a focal lesion of the cerebral cortex. Molecules in the IGF system were analyzed using in situ hybridization at different times following impact. We observed a dramatic up-regulation of insulin-like growth factor binding protein-2 (IGFBP-2) mRNA in cortical areas adjacent to the injury 24 h after impact, with a peak 10-fold increase engaging most of the ipsilateral cortex 2 and 3 days post-contusion. Seven days after the contusion, IGFBP-2 expression was only moderately up-regulated and again concentrated around the injury. IGFBP-4 mRNA levels increased 4-fold ipsilateral to the site of injury, with retained pattern of cortical expression. IGFBP-3, IGFBP-5 and IGFBP-6 mRNA all displayed distinct expression patterns in the brain but no significant changes were observed following injury. In contrast, IGF-1 mRNA levels were very low prior to contusion, but increased markedly at the site of injury with a peak at day 3. We were unable to detect any changes in the type 1 IGF-receptor or IGF-2 mRNA following contusion. The neuropeptide cholecystokinin (CCK) mRNA was clearly up-regulated following contusion, with an even distribution over the ipsilateral cortex. The expression pattern of molecules in the IGF system post-contusion differs in part to changes observed following hypoxic-ischemia or ischemia alone, perhaps reflecting different regulatory mechanisms depending on the type of injury.

Topics: Animals; Biomarkers; Brain Concussion; Cerebral Cortex; Cholecystokinin; Disease Models, Animal; Gene Expression; Image Processing, Computer-Assisted; In Situ Hybridization; Insulin-Like Growth Factor Binding Protein 2; Insulin-Like Growth Factor Binding Protein 4; Insulin-Like Growth Factor I; Male; Nerve Tissue Proteins; Rats; Rats, Sprague-Dawley; RNA, Messenger

Cholecystokinin (CCK) and gastrin show a potent influence on gastric secretion and motility, but their role in mucosal integrity has been little studied.. In this study the effects of CCK-8, pentagastrin, and duodenal oleate on acute gastric lesions induced by 100% ethanol were studied in rats.. CCK-8 was about 13 times more potent than pentagastrin in protecting the gastric mucosa against ethanol damage. CCK released by duodenal oleate also protected gastric mucosa against this damage. The protective effects of CCK-8 were almost completely abolished by the blockage of CCK-A receptors with loxiglumide, whereas the protective effect of pentagastrin was completely abolished by L-365,260. The protective effects of CCK, pentagastrin, or duodenal oleate against ethanol injury were accompanied by a marked increase in luminal content of somatostatin, suggesting that this peptide is implicated in this protection. The protective activity of CCK and pentagastrin against ethanol injury was accompanied by a significant increase in gastric blood flow. Inhibition of nitric oxide (NO) synthase with NG-nitro-L-arginine methyl ester abolished almost completely both gastric protection and hyperemia induced by CCK and pentagastrin. Addition of L-arginine, but not D-arginine, restored the protective and hyperemic effects of CCK and pentagastrin. Pretreatment with the sulfhydryl blocking agent N-ethylmaleimide also abolished the protective and hyperemic effects of CCK and pentagastrin. The hyperemia, but not the protection, afforded by CCK and pentagastrin was reduced after sensory nerve deactivation with capsaicin.. Both exogenous and endogenous CCK and pentagastrin exert protective activity against ethanol damage, and this effect is mediated through separate receptors, NO, and sulfhydryl-sensitive pathway.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Ethanol; Gastric Juice; Gastric Mucosa; Gastrointestinal Agents; Indomethacin; Male; Nitric Oxide; Oleic Acid; Oleic Acids; Pentagastrin; Rats; Rats, Wistar; Receptors, Cholecystokinin; Somatostatin

The main aim of our study was the investigation of gallbladder motility prior to gallstone formation in vivo in guinea pigs fed a lithogenic diet. In a first experiment guinea pigs were fed a lithogenic diet for 5, 15, 30 and 45 days. First gallstones (pigment calculi) appeared after 30 days diet application. The in vitro contractility after lithogenic diet remained unchanged. In a second experimental part the in vivo gallbladder contractility was measured in two experimental animal groups (control group and 21 days lithogenic fed guinea pigs). The isovolumetric pressure rise inside the gallbladder following the intravenous injection of 10(-9) mol/kg body weight ceruletid was the essential contractility parameter (intraluminal basal pressure 5 mm hg). Due to lithogenic feeding of 21 days--that means prior to gallstone formation--the isovolumetric pressure rise was significantly elevated (p < 0.01). Moreover we observed passive distensibility changes of gallbladder muscle due to muscular hyperplasia. The main result of this investigation is the fact that gallbladder muscle in guinea pigs fed a lithogenic diet response to ceruletid application with hypercontractility prior to provable pigment gallstone formation. However gallbladder hypomotility--believed to be a causal factor in cholelithogenesis--was not observed in our experimental conditions.

Topics: Animals; Biliary Dyskinesia; Ceruletide; Cholecystokinin; Cholelithiasis; Cholesterol, Dietary; Disease Models, Animal; Female; Gallbladder Emptying; Guinea Pigs; Muscle Contraction; Muscle, Smooth

Neuropathic pains have often been classified as opioid-resistant. Here, spinal (intrathecal) actions of morphine and nonmorphine opioids have been studied in a nerve ligation model of neuropathic pain in rats. Mechanical allodynia was evaluated using von Frey filaments. Nerve-injured animals exhibited allodynia that was stable for up to 6 weeks after the surgery. Morphine did not alter allodynia at doses up to 300 nmol (100 micrograms). In contrast, [D-Ala2, NMPhe4, Gly-ol]enkephalin (DAMGO), a high-efficacy mu opioid agonist, produced a significant, dose-related antiallodynic action. [D-Ala2, Glu4]deltorphin (delta agonist) produced a significant antiallodynic effect only at 300 nmol, reaching approximately 70% of the maximum. Coadministration of morphine with a dose of [D-Ala2, Glu4]deltorphin, which was inactive alone, produced a significant and long-lasting antiallodynic action that was antagonized by NTI (delta receptor antagonist); NTI alone had no effect. Although blockade of cholecystokinin-B (CCKB) receptors with L365,260 did not produce effects alone, a significant antiallodynic action was observed when coadministered with morphine; this elevation of nociceptive threshold was abolished by NTI. The finding that DAMGO, but not very large doses of morphine, produced antiallodynic actions suggests that the ability of mu opioids to alleviate the allodynia is related, in part, to efficacy at postsynaptic mu receptors. At an inactive dose, a delta agonist or a CCKB antagonist enhanced morphine antiallodynic efficacy in an NTI-sensitive fashion. CCKB receptor blockade may enhance endogenous enkephalin actions, resulting in enhancement of morphine efficacy through a mu-delta receptor interaction.

Topics: Analgesics, Opioid; Animals; Benzodiazepinones; Cholecystokinin; Disease Models, Animal; Drug Therapy, Combination; Male; Morphine; Pain Threshold; Peripheral Nervous System Diseases; Phenylurea Compounds; Rats; Rats, Sprague-Dawley

The present study determined the effect of pretreatment with "silent" selective 5-HT1A receptor antagonists on cholecystokinin (CCK)-mediated effects on rat behaviour in the elevated x-maze model of anxiety. In the absence of 5-HT1A receptor antagonists, non-sulphated cholecystokinin-octapeptide (CCK-8ns; 10 and 50 micrograms/kg, i.p.; 30 min prior to testing) produced an anxiogenic profile of behaviour on the x-maze, reducing the number of open arm entries and the number of exploratory head dips, while increasing the level of risk-assessment as measured by the number of stretched-attend postures. CCK-8ns did not, however, alter ambulatory activity. Two 5-HT1A receptor antagonists were employed in these experiments: (+)WAY100135 (the active enantiomer of N-tert-butyl-3-(4-(2-methoxyphenyl)piperzin-1-yl)- 2-phenylpropronamine) [sequence: see text] and WAY100635 (N-[2-[4(2-methoxyphenyl)-1-piperazinyl-1-piperazinyl]-N-2- pyridinyl)cyclohexanecarbonate [sequence: see text] trihydrochloride). When administered 10 min prior to CCK-8ns, (+) WAY100135 and 0.3 mg/kg s.c.) significantly attenuated profile of CCK-8ns. (+)WAY100135 was also demonstrated to significantly inhibit postsynaptic 5-HT1A receptor-mediated 8-OH-DPAT (8-hydroxy-2-(di-N-propylamino)tetralin)-induced 5-HT syndrome at the same dose used in the x-maze experiment. Neither (+)WAY100135 nor WAY100635 had any affects on ambulatory activity. These results support a CCK/5-HT1A receptor interaction in the modulation of aversion in rats exposed to the elevated x-maze.

Topics: 8-Hydroxy-2-(di-n-propylamino)tetralin; Animals; Anxiety; Behavior, Animal; Cholecystokinin; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Maze Learning; Peptide Fragments; Piperazines; Pyridines; Rats; Rats, Inbred Strains; Serotonin Antagonists; Sincalide; Time Factors

We studied the effects and the interactions of some candidate genes related to the pathogenesis of epilepsy using a domestic audiogenic epilepsy-prone rat, matched with the epilepsy-resistant Wistar rat, and primary fetal cerebral cortical neuronal cell cultures of both. The preliminary results showed that there was a possible abnormality of the CCK gene at the post-translational stage in the early postnatal period in P77PMC rat brain; the later rapidly increased rate of CCK-8 synthesis in the hippocampus and subcortical region may represent a compensatory response to the neuronal pathways involved in audiogenic seizures. CCK-8 can decrease the NMDA (1 microM)-induced free intracellular Ca2+ concentration, so it seems to be an inhibitory neuromodulator. In neuronal cell cultures, the NMDA (0.1 microM)-induced c-fos mRNA expression on culture day 18 in vitro was higher in P77PMC than Wistar rats (P < 0.05). Interleukin-1 (20 nM) can induce endogenous opioid mRNA expression and peptide release in neuronal cell cultures, which can be abolished by the addition of antisense oligos of c-fos/c-jun to cell cultures treated with interleukin-1. Both interleukin-1 and opioids can increase the free intracellular Ca2+ concentration, and their specific antagonists can reverse their effects, so they both seem to be excitatory neuromodulators in the CNS.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Epilepsy; Genes, Immediate-Early; Mutation; Neurons; Pilot Projects; Rats; Rats, Mutant Strains; Rats, Wistar

The aim of this work was to study in rats the temporal course of laboratory parameters and morphologic features in acute pancreatitis induced by cholecystokinin octapeptide (CCK-8) or by a closed duodenal loop. Pancreatitis was induced either with an overdose of CCK-8 (3 x 75 micrograms/kg at 1 h intervals) or by ligation of the duodenum on both sides of the bilio-pancreatic duct. The animals were examined at 0, 2, 4, 8, 16 and 24 h after AP induction. In CCK-8-induced acute pancreatitis, the pancreatic weight/body weight ratio (8.2 +/- 1.1 mg/g) and the amylase level (44.8 +/- 7.5 x 10(3) U/ml) were significantly increased vs. the controls (4.5 +/- 0.8 mg/g and 3.3 +/- 0.2 x 10(3) U/ml, respectively) 2 h after the intervention. The plasma CCK was significantly increased at 4 h (4.55 +/- 1.7 pM) and remained elevated thereafter. The tissue malonyldialdehyde concentration was significantly elevated at 8 h (0.28 +/- 0.07 mumol/mg pancreas) vs. the controls (0.20 +/- 0.02 mumol/mg pancreas). In closed duodenal loop-induced acute pancreatitis, the ratio pancreatic weight/body weight steadily increased during the study; it reached its maximum level at 24 h (7.1 +/- 0.5 mg/g) vs. the sham-operated control (4.8 +/- 0.9 mg/g). The serum amylase level was significantly elevated at 2 h (47.1 +/- 9.3 x 10(3) U/ml), and then decreased steadily. Plasma CCK values were significantly higher than the controls throughout the study. A significant increase in the tissue malonyldialdehyde concentration (0.94 +/- 0.15 mumol/mg vs. 0.20 +/- 0.01 mumol/mg pancreas) appeared at 4 h. Our data indicate that in CCK-8-induced acute pancreatitis the laboratory signs of pancreatitis are most expressed at 4 h, whereas the morphologic changes culminate 8 h, following the last CCK injection. In closed duodenal loop-induced acute pancreatitis, the histologic findings showed a progressive deterioration. Endogenous CCK and oxygen-derived free radicals seem to play a role in the pathogenesis of both types of acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Cholecystokinin; Disease Models, Animal; Duodenal Obstruction; Lipid Peroxidation; Male; Malondialdehyde; Organ Size; Pancreatitis; Rats; Rats, Wistar; Sincalide; Time Factors

The acute and long-term effects of a single injection of psychoactive drugs, methamphetamine or phencyclidine, were investigated by Northern blot to assess alterations in the cholecystokinin (CCK) mRNA in three areas of the rat brain. In the frontal cortex, there were no significant changes in CCK mRNA after the drug injection. In contrast, decreases in CCK mRNA were observed in the posterior cortex and the hippocampus from 30 min to 48 h after the drug treatment. The data suggest that CCK gene expression has different sensitivity to these psychoactive drugs within the cortices.

Topics: Animals; Brain Chemistry; Cholecystokinin; Disease Models, Animal; Male; Methamphetamine; Phencyclidine; Psychoses, Substance-Induced; Rats; Rats, Wistar; RNA, Messenger

Involvement of endogenous cholecystokinin (CCK) in the development of acute pancreatitis induced in rats by closed duodenal loop (CDL) was examined, and the effects of the potent and specific CCK receptor antagonist loxiglumide on this model of acute pancreatitis were evaluated. Plasma CCK bioactivity was markedly elevated 3 and 6 h after onset of acute pancreatitis. A single subcutaneous injection of 50 mg/kg body wt of loxiglumide 30 min before the induction of acute pancreatitis completely eliminated the hypercholecystokinemia. Loxiglumide given 3 h after the induction of acute pancreatitis suppressed plasma CCK bioactivity, which had risen up to 30-fold over basal value (0 h) at 3 h, to nearly the basal level. Loxiglumide pretreatment, in addition, significantly prevented the rise in serum amylase and lipase activity, as well as the increase in ascitic volume. It also ameliorated histological alterations of hemorrhagic and necrotizing pancreatitis. Reduction of plasma CCK bioactivity by loxiglumide after the onset of pancreatitis slowed the rate of progression of pancreatitis. However, pancreatic wet weight and cellular infiltration were not significantly influenced by loxiglumide treatment. These observations suggest that endogenous CCK is not involved in the initiation of acute hemorrhagic and necrotizing pancreatitis induced by CDL, but is involved in the development of pancreatitis in this model.

Topics: Acute Disease; Amylases; Animals; Cholecystokinin; Disease Models, Animal; Duodenum; Lipase; Male; Pancreas; Pancreatitis; Proglumide; Rats; Rats, Wistar

The hepatic secretion of supersaturated bile and gallbladder stasis are key events in cholesterol gallstone formation. The therapeutic value of cisapride, a prokinetic agent, was assessed in ground squirrels on a 1% cholesterol diet.. Biliary lipid secretion was measured directly and bile salt pool size assessed by isotope dilution ([14C]cholic acid). Gallbladder contraction was measured in vitro in response to cholecystokinin (CCK).. Cholesterol-fed animals had a combined hepatic secretory defect (a 53% decrease in bile salt secretion and also a 31% increase in cholesterol secretion). Adding cisapride restored bile salt secretion to control levels but did not affect cholesterol secretion. In cholesterol-fed animals, the cholesterol saturation index of gallbladder bile more than doubled and cholesterol crystals developed; cisapride markedly reduced cholesterol saturation, thus preventing crystal formation. Gallbladder contractility, measured in vitro in response to CCK, decreased 23% in animals on the 1% cholesterol diet; cisapride restored the CCK dose-response curve to normal. The bile salt pool as assessed by isotope dilution was similar in all groups.. Thus, lithogenic bile develops in this model because of reduced bile salt secretion and increased cholesterol secretion. Cisapride renders biliary lipid composition towards normal by enhancing gallbladder (and possibly intestinal) motility and cycling of the bile salt pool, thereby increasing bile salt secretion.

Topics: Animals; Bile; Bile Acids and Salts; Carbon Radioisotopes; Cholecystokinin; Cholelithiasis; Cholesterol, Dietary; Cholic Acids; Cisapride; Disease Models, Animal; Dose-Response Relationship, Drug; Gallbladder; Gallbladder Diseases; Gallbladder Emptying; Lipid Metabolism; Lipids; Male; Piperidines; Sciuridae; Serotonin Antagonists

Studies in animal models suggest that oxygen radicals may be important in the pathogenesis of acute pancreatitis. Because glutathione is an essential component of the defense against radical-mediated cellular injury, we investigated whether pancreatic glutathione content is influenced by inducing acute pancreatitis and whether augmenting the intracellular supply of glutathione would alter the course of pancreatitis. Caerulein, a decapeptide cholecystokinin analogue, induces acute necrotizing pancreatitis in mice when given in high doses (50 micrograms/kg per h) over a period of 6 h. The pancreatic glutathione content (total, GSH + GSSG) in mice treated with high-dose caerulein fell to 17% of normal within 4 h of beginning caerulein and recovered toward normal after discontinuing caerulein treatment. Mice treated with glutathione monoethyl ester (20 mmol/kg 1 h before caerulein, 10 mmol/kg 3 and 7 h after starting caerulein) were found to have blunted depletion of pancreatic glutathione, diminished histologic evidence of pancreatitis (necrosis, inflammation, and vacuolization), and lower serum amylase values compared with mice treated with caerulein alone. These findings suggest that the profound depletion of pancreatic glutathione caused by hyperstimulation of the pancreas with caerulein is critically important in the pathogenesis of acute caerulein-induced pancreatitis.

Topics: Amylases; Animals; Ceruletide; Cholecystokinin; Disease Models, Animal; Female; Free Radicals; gamma-Glutamyltransferase; Glutathione; Isoxazoles; Mice; Pancreas; Pancreatitis; Radiation-Protective Agents

We evaluated the effects of a new cholecystokinin (CCK) receptor antagonist, loxiglumide, in a model of mild pancreatitis induced by repeated injections of cerulein and in a severe necrotizing form of pancreatitis induced by retrograde ductal injection of sodium taurocholate (NaTc) in rats. A single subcutaneous injection or oral administration of 50 mg/kg of body weight of loxiglumide almost completely reduced the increases of serum amylase activity and pancreatic wet weight, and caused histologic improvements of the cerulein-induced acute pancreatitis when given 30 min before the first cerulein injection. Loxiglumide was also effective in reducing the elevated serum amylase activity, pancreatic wet weight, and histologic alterations even when administered after the induction of acute pancreatitis. However, loxiglumide offered no apparent beneficial effects when given 30 min before and 3 h after the induction of acute pancreatitis by NaTc as determined by changes in serum amylase activity, pancreatic wet weight, and histology. These results do not necessarily suggest that CCK is not important in the pathogenesis of pancreatitis, but do suggest that the sole blockade of peripheral CCK receptors is ineffective against NaTc-induced severe necrotizing pancreatitis.

Topics: Acute Disease; Animals; Ceruletide; Cholecystokinin; Disease Models, Animal; Glutamine; Male; Pancreatitis; Proglumide; Rats; Rats, Inbred Strains; Receptors, Cholecystokinin; Taurocholic Acid

Acute edematous pancreatitis was produced in rats by subcutaneous administration of caerulein. Pancreas weight, pancreas histology and plasma amylase were used as endpoints to quantitate the severity of the syndrome. A caerulein dose of 10 micrograms/kg.hour produced the most severe pancreatitis, whereas at 5 micrograms/kg.hour the values were half-maximal. The pancreatic lesions were characterized by edema, formation of cytoplasmic vacuoles, leukocytic infiltration, necrosis, and with time (12-hour caerulein infusion) dilated acini. Cholecystokinin octapeptide also produced pancreatitis when given at ten times the dose required for caerulein (50 micrograms/kg.hour instead of 5 micrograms/kg.hour). Carbachol did not induce pancreatitis. Two prostaglandins, 16,16-dimethyl prostaglandin E2 injected subcutaneously and prostaglandin E2 infused subcutaneously, dose dependently prevented caerulein-induced pancreatitis (pancreatic edema, leukocytic infiltration, and necrosis) and reduced the number and size of intracellular vacuoles. The ED50 were 15 to 25 micrograms/kg for 16,16-dimethyl prostaglandin E2 and 90 micrograms/kg.hour for prostaglandin E2. Neither prostaglandin, given at doses inhibiting the development of pancreatitis, prevented the retardation of gastric emptying caused by caerulein, a finding suggesting that the prostaglandins may act specifically on the effect of caerulein on the pancreas but not on caerulein receptors in gastric smooth muscle. Indomethacin, an inhibitor of prostaglandin synthesis, and methscopolamine bromide, an anticholinergic agent, had no effect on caerulein-induced pancreatitis. We concluded that prostaglandins of the E type prevent the development of caerulein-induced pancreatitis. The mechanism by which prostaglandins protect the pancreas may involve stabilization of lysosomes within the acinar cells and inhibition of intracellular activation of pancreatic digestive enzymes.

Topics: 16,16-Dimethylprostaglandin E2; Amylases; Animals; Carbachol; Ceruletide; Cholecystokinin; Dinoprostone; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Indomethacin; Infusions, Parenteral; Organ Size; Pancreas; Pancreatitis; Prostaglandins E, Synthetic; Rats

Oral pancreatic enzyme replacement therapy generally benefits patients with severe pancreatic deficiency. However, the fate of oral pancreatic supplements in the digestive lumen and their possible effects on circulating gut hormones are only partially known. The purpose of this article is to validate an experimental model that produces total pancreatic insufficiency in pigs, and to study the fate of orally administered Eurobiol, a whole pancreas lyophilized preparation, and its effects on circulating plasma levels of five digestive hormones. Pancreatic insufficiency was created by pancreatic duct ligation, and the duodenal, jejunal and ileal contents were sampled through cannulas before a normal meal and 0.5-24 h later. Blood samples were taken at the same times, and plasma neurotensin, pancreatic polypeptide, secretin, cholecystokinin (CCK), and gastrin were measured. In pigs with pancreatic insufficiency, Eurobiol, given during the meal, induced a significant increase in all enzyme activities in the duodenum and the jejunum, and in the levels of amylase, trypsin, and chymotrypsin in the ileum, relative to placebo. In the duodenum, the peak concentrations of enzyme activities were 19, 11, 17, and 29% (p less than 0.001) of the postprandial peak activities measured in control pigs with an intact pancreas for lipase, amylase, trypsin, and chymotrypsin, respectively. In the jejunum, the same activities were, respectively, 30, 11, 25, and 36% (p less than 0.01-0.001) of normal peaks. In pigs with pancreatic insufficiency, basal and integrated meal-stimulated neurotensin levels were increased; basal, peak, and integrated meal-stimulated pancreatic polypeptide and secretin levels were increased, whereas gastrin and CCK were not different from controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Administration, Oral; Amylases; Animals; Cholecystokinin; Chymotrypsin; Disease Models, Animal; Exocrine Pancreatic Insufficiency; Gastrins; Intestines; Lipase; Male; Neurotensin; Pancreas; Pancreatic Extracts; Pancreatic Polypeptide; Secretin; Swine; Trypsin

A decrease of both hypothalamic and cortical CCK occurred in the brain of rats killed 8 hours after hepatic artery ligation following portocaval anastomosis. Brain CCK depletion was not reproduced by exogenously provoked hyperammonemia nor by insulin-induced hypoglycemia, thus suggesting a central mechanism for the derangement of the CCKergic system in the course of acute liver failure.

Topics: Ammonia; Animals; Blood Glucose; Brain; Cerebral Cortex; Cholecystokinin; Disease Models, Animal; Hypothalamus; Liver Diseases; Male; Rats; Rats, Inbred Strains

The occurrence of seizure activity in human temporal lobe epilepsy or status epilepticus is often associated with a characteristic pattern of cell loss in the hippocampus. An experimental model that replicates this pattern of damage in normal animals by electrical stimulation of the afferent pathway to the hippocampus was developed to study changes in structure and function that occur as a result of repetitive seizures. Hippocampal granule cell seizure activity caused a persistent loss of recurrent inhibition and irreversibly damaged adjacent interneurons. Immunocytochemical staining revealed unexpectedly that gamma-aminobutyric acid (GABA)-containing neurons, thought to mediate inhibition in this region and predicted to be damaged by seizures, had survived. In contrast, there was a nearly complete loss of adjacent somatostatin-containing interneurons and mossy cells that may normally activate inhibitory neurons. These results suggest that the seizure-induced loss of a basket cell-activating system, rather than a loss of inhibitory basket cells themselves, may cause disinhibition and thereby play a role in the pathophysiology and pathology of the epileptic state.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Electric Stimulation; Epilepsy; gamma-Aminobutyric Acid; Hippocampus; Immunologic Techniques; Interneurons; Male; Neural Inhibition; Rats; Somatostatin; Time Factors; Vasoactive Intestinal Peptide

Neurochemical studies of post-mortem human parkinsonian brains have demonstrated specific alterations in neuropeptide concentrations within the substantia nigra and striatal structures. The drug, 1-methyl-4-phenyl-1, 2, 3, 6 tetrahydropyridine (MPTP) has been reported to act as a selective toxin to nigrostriatal dopamine neurons, and induces a parkinsonian-like syndrome in primates. In this study, marmosets developed features typical of Parkinson's disease following treatment with MPTP for four days. The effects of MPTP treatment on the concentrations of dopamine and neuropeptides were determined and changes compared with those reported for Parkinson's disease. It was found that within the substantia nigra, substance P concentrations doubled following treatment with MPTP; in contrast, concentrations of vasoactive intestinal peptide and neuropeptide Y were significantly reduced. No changes were observed in the concentrations of six other neuropeptides measured in this region, notably cholecystokinin. Despite marked depletion of dopamine within the caudate nucleus and putamen, concentrations of all neuropeptides within these structures remained unchanged with the exception of an isolated reduction of neuropeptide Y within the putamen. Somatostatin concentrations within the frontal cortex and hippocampus were significantly elevated in the marmosets treated with MPTP. These neuropeptide changes in the CNS contrast with those reported for Parkinson's disease. In view of the autonomic dysfunction associated with Parkinson's disease, peripheral concentrations of neuropeptides were determined. Significant depletion of neuropeptide Y was identified in the ureter, adrenal and cardiovascular tissue. Thus the neurochemical changes induced by MPTP may not be as selective as previously reported.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Brain Chemistry; Callitrichinae; Cholecystokinin; Disease Models, Animal; Dopamine; Female; Kidney; Male; Neurotensin; Parkinson Disease, Secondary; Pyridines; Substance P; Vasoactive Intestinal Peptide

The effects of the cholecystokinin (CCK)-receptor antagonist proglumide, the protease inhibitor gabexate, and the hormones secretin and cholecystokinin-octapeptide (CCK-8) were studied in a model of acute hemorrhagic pancreatitis induced by feeding mice a choline-deficient, ethionine-supplemented (CDE) diet. Injections of gabexate and proglumide from initiation of CDE diet (before induction of pancreatitis) increased survival from 37% (diet alone) to 85 and 75%, respectively, and also ameliorated histological alterations and increases in serum amylase concentration and pancreatic activated trypsin. Secretin had no major beneficial effect. When proglumide or gabexate were given after induction of pancreatitis, proglumide still increased survival to 75%, whereas gabexate no longer did. Injection of nontoxic doses of CCK-8 before proglumide or gabexate injections completely abolished all beneficial effects and also increased the severity of pancreatitis due to CDE diet alone. Blockade of CCK receptors and early inhibition of protease activity may be beneficial in severe acute pancreatitis. Cholecystokinin appears to play a contributory role in the development of pancreatitis.

Topics: Acute Disease; Amylases; Animals; Cholecystokinin; Choline Deficiency; Disease Models, Animal; Ethionine; Female; Gabexate; Guanidines; Hemorrhage; Mice; Pancreas; Pancreatitis; Proglumide; Receptors, Cholecystokinin; Secretin; Time Factors; Trypsin

Pancreatic insufficiency was induced in rats by a single injection of 50 microliter oleic acid into the pancreatic duct over a period of 3 min. Exocrine tissue was destroyed within 3-6 days, and after 6 weeks the remaining pancreas equaled 2.7% of the original organ. The rats showed retardation of body weight in spite of normal food intake. After 7 weeks the fecal weight increased by 23%, and the fecal chymotrypsin activity decreased by 90% compared to controls. At this time plasma cholecystokinin (CCK) concentrations were significantly elevated. The amylase content in the remaining pancreas was reduced by 99%, and trypsin content was reduced by 93%. Unstimulated protein discharge from the remnant pancreas in vitro was threefold higher compared to secretion from control tissue. Thus a simple, reproducible model for inducing persistent pancreatic insufficiency was developed. To compensate for the loss of exocrine tissue, the remaining acinar cells adapt by a CCK-mediated increase in protein secretion.

Topics: Adaptation, Physiological; Amylases; Animals; Cholecystokinin; Digestive System; Disease Models, Animal; Male; Oleic Acid; Oleic Acids; Pancreatic Diseases; Rats; Rats, Inbred Strains; Trypsinogen

Topics: Adenocarcinoma; Animals; Carcinogens; Cholecystokinin; Cricetinae; Disease Models, Animal; Neoplasm Metastasis; Nitrosamines; Pancreas; Pancreatic Juice; Pancreatic Neoplasms

Topics: Animals; Basal Ganglia; Brain Chemistry; Cell Survival; Cholecystokinin; Corpus Striatum; Disease Models, Animal; Humans; Huntington Disease; Ibotenic Acid; Rats

Alterations in the pancreatic secretion of fluid and of enzymes in response to either pilocarpine (15 mg/kg) or an octapeptide of cholecystokinin (0.1 microgram/kg) have been found in rats that received daily injections of reserpine (0.5 mg/kg) for 7 days. During a 3-hr secretory period, significant reductions in the volume of pancreatic juice and in the total output of protein, amylase, and trypsin were observed in these animals. In the first hour of the secretory response, however, protease output was increased in the treated animals, particularly that of chymotrypsin, which was also increased in the longer secretory period following pilocarpine, but not cholecystokinin, stimulation. Zymogen granules isolated from the pancreas of the treated rats by differential centrifugation in a 0.3 M sucrose buffer had increased specific activities of the proteases when compared to those of untreated controls. Ultrastructurally, zymogen granules isolated from the pancreas of the treated rats showed changes in density, with bizonal and trizonal configurations being frequently observed, and had less distinct limiting membranes. In some, the membrane appeared broken at intervals, and there was granular material, presumably derived from the granule contents, lining the surface of the granule. It is concluded that pretreatment with reserpine inhibits fluid secretion and alters enzyme secretion in the rat exocrine pancreas. The latter effect is related to a nonparallel storage of amylase and proteases in the secretory granules induced by the drug treatment, probably through an action on protein synthesis or intracellular transport. An accumulation of proteases may lead to activation of these enzymes and to granule lysis. Inasmuch as the reserpine-treated rat has been proposed as an experimental model for cystic fibrosis, these findings are relevant in terms of possibly pathogenetic mechanisms in this disease.

Topics: Amylases; Animals; Cholecystokinin; Chymotrypsin; Cystic Fibrosis; Disease Models, Animal; Male; Pancreas; Pilocarpine; Rats; Reserpine; Trypsin

Topics: Amylases; Animals; Cholecystokinin; Cystic Fibrosis; Disease Models, Animal; Electrolytes; Male; Organ Size; Pancreatic Juice; Proteins; Rats; Reserpine; Secretin; Time Factors

Effects of irradiation on the pancreas was studied in 6 dogs receiving a dose equivalent to the biologic effect of 4000 R/6 weeks (with a nominal stnadard dose of 1175 rets) given to patients with Hodgkins disease. After control secretory, histologic and pancreatographic studies, 6 Thomas fistula dogs were subjected to 2400 R tumor dose over two weeks. There was a biphasic response to secretin alone or secretin with cholecystokininpancreozymin. An initial hypersecretion occurred at 2 weeks --volume was increased, but bicarbonate and enzyme output remained unchanged. Thereafter there was a progressive reduction in volume, bicarbonate and enzyme outputs ( greater than 90% after 3 months). Histology showed early ductal reduplication but with progressive fibrosis, features compatible with chronic pancreatitis. Pancreatic insufficiency may contribute to post-irradiation gastrointestinal symptomatology. Close field irradiation of the pancreas results in actual destruction of the parenchyma.

Topics: Animals; Bicarbonates; Cholecystokinin; Disease Models, Animal; Dogs; Female; Male; Pancreas; Pancreatic Diseases; Pancreatic Juice; Radiation Dosage; Radiation Injuries, Experimental; Secretin

In this study, 37 guinea pigs were classified, on the basis of histologic examination of the pancreas, into three categories: nondiabetic, latent diabetic, and overt diabetic. In order to compare the exocrine pancreatic function in these three groups of animals, pancreatic secretion was collected from each animal following an intravenous infusion of secretin and pancreozymin. Pancreatic enzyme activity, bicarbonate concentration, and the total volume of pancreatic secretion were all significantly decreased in guinea pigs with overt diabetes, but not in those with latent diabetes mellitus. Pancreatic histologic changes characteristic of both latent and overt diabetes were beta-cell hyperplasia and generalized fatty degeneration of the acini. Only the animals with overt diabetes showed total degranulation and severe vacuolation of theta-cells. The same type of exocrine pancreatic dysfunction observed in guinea pigs with spontaneous overt diabetes mellitus is found in human diabetics, and is particularly common in the juvenile type. The guinea pig, therefore, appears to be a suitable animal model for the study of human juvenile diabetes mellitus.

Topics: Amylases; Animals; Bicarbonates; Blood Glucose; Cholecystokinin; Diabetes Mellitus; Disease Models, Animal; Guinea Pigs; Islets of Langerhans; Lipase; Male; Pancreas; Secretin; Trypsin

Intra-intestinal pressure was recorded with open-tip catheters in experimental low small-bowel obstruction in the cat. At zero time the pressure was 2-4 mmHg. After 72 hours sustained intraluminal pressure ranged mainly between 5 and 10 mmHg. Long periods of inactivity alternated with short bouts of spontaneous bowel activity. During activity the pressure rose to about 20 mmHg. In motility responses elicited by cholecystokinin, momentary pressure waves amounting to 40-50 mmHg were recorded. The result of simple mechanical obstruction is predominantly a bowel distension, whereas the magnitude of sustained intraluminal pressure is rather modest. Possible effects of distension on intestinal microcirculation are discussed.

Topics: Animals; Cats; Cholecystokinin; Disease Models, Animal; Gastrointestinal Motility; Intestinal Obstruction; Intestine, Small; Pressure; Stimulation, Chemical